I'm new so I don't know the map names. But my whole team was working pretty good together. We were rolling into their base, blowing holes in the wall. And totally with out communication, about 6 of us just stormed the walls all at the same time. I looked left and was like "oh fuck. this is badass." Not that exciting I guess. But the game really grabbed me then for some reason. The sound is excellent, the rumbles crackles and thumps are great.

The first time I played Squad Deathmatch, I was put in a very competent team.  I played an Assault, another guy was a Recon, and the last one was an Engineer.  Although we first were just on all sides of the map, attempting to get as many kills as possible, we eventually all garrisoned up inside a house.  Before we knew it, we were circling around keeping each window covered, and the bodies were just piling up outside.  The Engineer kid has a mic and yells, "Out of ammo!  Both guns!".  I throw down an ammo box, and the shoosting continues.  Eventually, as we jump out to about a 20 kill lead, people start shelling the house with grenades and RPGs.  The Recon dude goes down when the wall he's in cover behind gets blown up, and I rush to cover the huge opening, gunning down the shooter as he's reloading his launcher.  The Recon guy soon is back in the fight, and continues sniping. 
At matches end, we had racked up the 50 kills with the next team at about 35.  I got the best player medal for my efforts, and having won a round in Squad Deathmatch, I unlocked the achievement for winning a round in each game type. 
It all certainly made me say, "SHIT YEAH".

its hard to define my oh shit moments because this whole game is an oh shit moment. 

Crashed a helicopter in enemy territory and found out I was right behind 10 enemy players and began firing, only killed 4 but the rest were mowed down by my squad, it was fucking awesome.

Taking a dude out after he blew up my heli.
 
The thing is though, i jumped out of the chopper and it blew up, and i slammed into him from above!
 
OH FUCK YES

when i shot a noob helicopter pilot with a tank shell

one of my squad shot down a heli... It landed really really fuckin close to me

I played that island hopping level for the first time the other day, and I went off on some dudes with the SV-shwhatever sniper. Reminds me of the scout from counterstrike. Relatively weak, but fucking quick and lethal.

sniping someone out of a chopper was pretty great!

every time i stab an enemy on the face for a knife kill & get a dog tag for doing that hehehe!

Watching my teammate get squashed by a falling Blackhawk, epic.

I randomly fired a bullet at a moving chopper with a sniper rifle and managed to kill the pilot. I didn't even know that it was possible but it was one of the luckiest shots I ever achieved in gaming.

My oh shit moments? Getting headshots (also shameless promoting of my montage):
 
 

Knifing a guy IN THE FACE!

my biggest moment was on that rush map with the light house. the second m-com stations. i want to the light house went all the way to the top. i saw a dood all the way at B so i fired my gustav =D boom killed 3 people all the way from the light house XD

When I was driving a jeep with me and my mates, and then narrowly dodged a tank shell that threw up sand and dirt into the air as well as making a deafening sound. We got to the enemy base and I just went, FUCK YES. 
 
Not much, but it was fun.

Just last night, actually.
 
Myself and Snipzorz are playing at Panama, and we're Ruskies, so A is the farthest point from us. We roll around in a tank for awhile, kicking ass. I'm an engineer, so I'm maining the main gun and repairing when I need to, when i do so Snip hops on the big boy and keeps us safe. It works great for 10 minutes or so, we're racking up points left and right. Eventually get get cocky, and head to A, and lose our tank.
 
So here we are, myself as an Engie, and Snip as a recon with the Saiga and a Mortar strike. We hold off everyone coming at us for at least 15 minutes. I'm rocketing tanks and APC's, Snip is calling in mortar strikes. They keep throwing themselves at us, and we our ground. Our team ends up winning the round by 45 kills.
 
It was fucking beautiful.

I think I have the oh shit yes moment every day I play! Found some hardcore server yesterday and the opposing team was reaaallly rough. The following map was that retarted dusk snow map that I hate, but I played on since i was 50 points away from the M16. Finally I unlocked it and equipped it..and daammnnn that thing is bad ass. We ended up winning the round and I was 3rd on the board.

Havent played much, but shooting a heli's gunner and watching his body collapse back into the chopper and the watching as the chopper gets smashed into by an RPG second later. And also the first time you ever take aim from a fair distance with an assault rifle and then watch as the little person way away collapses when you pull the trigger. :D 

Both of mine involve the quad bike, first day I was on the huge desert map (still dont know the names, Arica?) Any way I wanted to get close to the enemy base and plant anti tank mines. So I'm racing from the base and two of the scripted A-10 warthogs fly right over nearly taking me out :P My instinct was to avoid, hit a burnt out car and got some air, enemy tank fires and the shell flies right under me, jump off bike, lay tank mine and EXPLODE. 
 
Second was joining about 5 mins after the start of a match on the lighthouse map, jumped on the bike, my friend sitting next to me spawned on the back. Hit the gas and fly through the jungle part my friend constantly telling me we are going to crash, I cant exactly see where I'm going but I see a clearing and head for it. Fly through all the leaves ON TO the roof of a building, over an armored vehicle that gets blown to shit and land in the tiny hole in the wall at B. Turned to my friend and he was just looking at me like :O We got out planted B and absorbed the awesome.

Driving a tank around the back of the first Arica harbour base as an attacker blowing a hole in the wall, then the wall of the prefab with the "B" m-com station, hopping out mowing down the sniping rat who'd come to see whats up, planting the bomb blowing it then jogging across to A killing 3 more guys as I got their to help us blow that m-com too. It all took about thirty seconds to a minute, was glorious.*
 
 
*600 posts, woop!

There are too many to mention all of them (after all this is BF, awesome moments occur often).
 
These two happened yesterday: Driving an atv into the enemies base, flanking and knifing 5-6 people and escaping in their tank, kiling our way out. This was with me and 2 other friends.
 
Circling slowly around the enemy base in a blackhawk mowing down 8-10 enemies with the minigun before getting shot down. We jumped out of the spinning chopper in parachutes, landed and killed a couple of guys and were able to plant explosives on one of the capture points.

I was playing a round as engineer on Arica Harbor, the second part, the town part. While I'm crossing the main street, out of the corner of my eye I see a Humvee rushing towards me. I go like, "shit, shit, shit! I'm not going to be able to outrun this thing."
So I quickly pull out my RPG, fire, and it hits the Hummer literary 5 feet away from me. I watch as it does a front flip above me and smashes to the ground right behind me. Fuck yes! 

Getting 590 points in a single feed, I probably killed two or three people, revived another two or three and and a couple of med-kits out. I felt so proud.

Playing with some people from the JPAG (Joystiq Podcast Appreciation Group - great group of guys and gals) and 2 awesome matches of Rush. New to this game and the franchise and had been wondering when the hype about teamwork was going to come to true. Probably the best multiplayer experience I've had on XBL. Very intense with defending the last bombsite for a good 10 minutes before losing with them having just 4 spawn tickets left and then won the next round as attackers with just 3 tickets left. Great feeling.
 
However, that was tarnished when the next day I was playing with a bunch of strangers and no one was using voice chat and half my team was literally RUNNING AWAY from the bombsites when the bombs were armed because they were afraid of getting killed and hurting their K/D ratio. Worst multiplayer experience on XBL.
 
Loving this game when playing with people I know, but with strangers, it's really hit or miss.

Shooting down a heli, and then watching it crash into another heli and kill 5 people was prolly my biggest oh shit moment so far.

Taking down a blackhawk with the AT4, only to watch it crash into my squad mates, killing them instantly.

Probably too many to pick just one.
But the other day I laid down 6 AT mines (double explosives perk) and absolutely demolished basically the entire team at the same time as they rolled down in a big convoy. Explosions, wreckage and fire everywhere, the points were tallying forever.

Getting a head-shot whilst parachuting down at the start of a game of Rush. I randomly took a shot with my recon class to the other side of the map and it got a head-shot.

I was playing some Atacama Desert (Conquest with the two helicopters). 
 
The game had already started, so I spawned at our base and got into an ATV, I sped along the outside of the map doing some jumps off the sandbags and enter the enemies base on the left side. I find a nice little bush with a tree right next to the helipad. I figured that no one could see me and decide to wait for the heli to spawn.  
 
Then I see one person go to the helipad, and a few seconds later 3 more people spawned on him, they were all shooting tracer tarts at each other and standing still.  
 
I figured it wouldn't be too long until the helicopter spawned, so I pulled the trigger. 
 
I place a nice burst on this one guys head, then another on the 2nd, then sprayed into the body of the 3rd, and RPG'd the 4th. 
 
All from a little bush. 
 
(Oh, and I got the helicopter, I love happy endings)

I managed to hit a speeding ATV flying by me with a guided AT missile. It was awesome. Haha.

I had too many to count. Yesterday I sniped two Black hawk gunners in one round. In the same round I also went head to head with a dude on a quad. Using only my pistol I blew up his quad right before he hit me which caused fire and debris to stream over my head. 

Mass killings with the Saiga, and I've got witnesses to this. I didn't die for quite a while during this time as well, important to note that. I have very low standards of excellence, yes.

I randomly shot a tank round into the sky because I saw a helicopter and somehow I managed to hit it and destroy it for a double kill o_O. Also, during the demo I was in a transport helicopter with three other dudes and we got shot down waaay behind enemy lines. We all managed to bail out and survive, and we fought our way all the way back to our own territory. It was so awesome.

enemy apache was obliterating our team on port valdez, and i just fired a random rpg at it and hit the very end of its tail. i literally jumped out my seat and yelled FUCK YEAH.

blew a hole in an attic where snipers camp (they didn't want to move from there) then i gently parked the mini heli into it and took out 3 snipers :)

mine was just randomly flying off a hill on my atv, and landing on 3 douche snipers for a triple kill. but definitely by far, the biggest oh shit moment i've seen was this guy turning his helicopter into a giant hand grenade.

Anytime you get the last M-Com destroyed with <5 tickets

I love slapping C4 on quads, waiting for some overeager sap to hop on...then blowing their ass up. SO GOOD.

Last night I saw a Blackhawk get taken out by a mortar strike. That was awesome.

I sniped a chopper pilot and got a headshot, sending the heli crashing down. That's when I didn't even know we could kill pilots.

Attacking in rush taking out the last m-com with 7 tickets left I'm an engineer and we have another engineer and a assault in a bradley we storm the last base  with me and the other guy healing, i plant the charge then i get shot down, the tank blows up, respawn run in there and kill the guy trying to dissarm and we win with 1 ticket left

No scoped a pilot out of Havoc (I believe thats what they are called)
 
And
 
Sniped a guy (headshot) on the little cliff that every sniper goes to on port valdez.
 
He was on the sniper perch at the second to last bomb site, It was crazy. The bullet dropped SO far.

When I was on Laguna Presa on conquest, I saw that there were like 3-4 snipers constantly going to the rock plateau near the waterfall, so I kept mortar striking them, and sniping them for like 2 rounds before they got the tip.  That was pretty awesome. 
 
Another shit yeah moment was on Atacama Desert, I was medic and for some reason I was in the middle of the map, and I was easily able to see and snipe all the snipers around on the other spawn points. So much fun to kill them, I was sniping with my pistol too, once, and I got a tank kill from across the map. I sniped with everything, basically and that was such a fun random round. 

Taking down 3 helis, 2 UAVs and 11 enemies in a row on the first base at Isla Innoceties with the mounted gun on the hill behind the sandbags.
But then when the game was over there was a server disconnect and i decreased a huge ammount of XP instead.  Yay anti-reward system!

This thing happened totally by accident as the tank driver wasn't on my squad but we had just took a base and I was advancing forward to the next one. On getting there a tank driver behind me just started firing into the buildings in front of me. I just ran straight to the site through three buildings that got blown apart as I sprinted through them.