Just about to finish uni for the year and as i havnt been able to play games online whilst ive been here i was just wondering which one i should buy when i get home? Ive played a bit of MW2 and other call of duty games but never played BF.  

BF is kinda clunkier, especially on the 360, but if you have friends to play with it's a much greater experience. MW2 is more of a solo effort most of the time.

" @FirePrince: With work and going out im not going to have time for that. Plus i want to focus my efforts into one so i can improve faster. At the moment im kind of thinking BF. Buts that just because ive played quite a bit of MW2 this year (but it was locally so not really the full experience). Think ive got more friends who will be playing MW2 though.  "

Best to see what you friends are playing and get that, course with the second map pack coming out for MW2 I'm sure that will take a surge in activity.

I'm biased because I prefer MW1 over MW2 in terms of multiplayer. I'm also biased because I think BF:BC2 is the best FPS multiplayer experience I've had since Counterstrike, and I hated Battlefield up until this game. It certainly contains a depth unknown to Modern Warfare.

You HAVE to play Battlefield with a group, lone wolves, just get murdered. 
 
MW2 is fun if you want to play by yourself.  play MW2, so i can have some music playing the background so I dont have to hear anyone.

Best think about what u want. In Bc2 u cant win when your team sucks. The weapons are not very powerful, so u likely die at some point if u meet more than 1 or 2 guys.

BFBC2's multiplayer is better than MW2's multiplayer. It's not as frantic and is more realistic....plus it has a load of vehicles. The single campaign seems shorter though.

" BFBC2's multiplayer is better than MW2's multiplayer. It's not as frantic and is more realistic....plus it has a load of vehicles. The single campaign seems shorter though. "

There are a lot of people who have an intense h8t against MW2 simply because it’s not always easy for them to get a good experience playing, usually cause there just not good enough or they have been in too many games where people use cheap tactics and they don’t know how to counteract it. They also think that being the most hyped shooter it should satisfy them better by giving them a hand job or something. But MW2 is deep experience that offers a lot if you know what you’re doing and still makes my heart race, the spec ops mode I played with a buddy alone was worth full price and then there’s the single and multiplayer.    

I've seen threads like this across the internets since BC2 released back in early March. I think anyone who directly compares the two is doing a real disservice to both games. They're 2 totally different kinds of team based shooters. BC2 leans more towards tactical and realism gameplay. While someone in the thread said you will be slaughtered playing by yourself, I think that's quite an overstatement. I play it occasionally these days, 1-2 hours a week and 90% of the time hop on for a few rounds solo and have a good time. I do fine and never get a feeling of wanting to shut my 360 off due to rage or anything like that. 
 
MW2 is the more arcadey experience of the two. Faster paced play and smaller maps, leading to much more firefights. I have a couple weeks worth of time logged on MW2 at this point, and rarely play more than an hour a week these days. I won't say MW2 is a bad game, because I had lots of fun playing it. I just burned myself out on it. I've been logging more time on COD4 as of late. It's much more focused on the guns, less about the killstreaks (which are cool) but there isn't explosions and bombs going off every 30seconds.
 
If I had to recommend one, it's gotta be MW2. You said you've played it already but local only. Multiplayer is really it's selling point. It has 4 or 5 times the online gameplay types that BC2 has, so the variety is there. If I understand OP correctly when he says he has a limited amount of playtime, MW2 is the better choice. Matches last 10-15m depending on the game type and is easy to pickup for a few rounds and come back to later.

My vote would be for BC2 but I'm a fan of the Battlefield series from way back. MW2 didn't really stick with me like MW1 did but that's probably because of the increased number of foul mouthed youth.

having played MW2 for about 200 hours at this point i'd go with BFBC2. It's a better team based game and has less bullshit (I.E Overpowered tactics/exploits) And of course, the development team for BFBC2 still exists and as such can provide balance patches as opposed to MW2.

Hard to compare due to the massive difference in gameplay style, but I'd much rather play BC2 just cos it has so much more to it.

Never cared for MW2, if  I could I would pick up BC 2, because that looks like more fun.

I haven't played any Call of Duty, but I can say that the Battlefield game is an excellent experience when there is no lag (it isn't optimized for bad ISP's) and when your team sucks. It's really good that they introduced the experience/rank system because even if your team sucks you can still do a hell of a job by yourself and the points will reflect that. I tend to find that I am the player of the match (or second best) fairly often when I'm in a good squad. The game was putting me in the best squad all the time until just recently. Over the past week I have noticed jerk-offs that want to ruin the game, let me explain, these guys try to join there friend's game but because there friend's team is full, they are put into the other team (my team usually) and they deliberately make your team lose to make their friend win. They do it by placing C4's all over the stations you are supposed to be defending and then ignite it. You don't necessarily realize what's going on when you are busy shooting the shit out of the 'enemies' approaching the door, while just behind your back the sneaky bastard who is on your team is placing bombs on the station you are supposed to defend. 
 
Also, the game is unfairly balanced normally, so you have to switch the game to hardcore mode in the settings before you start, that way your weapons are more likely to actually kill your enemies when you shoot them and the rest of your team have a higher percentage of people trying to complete the objective (it is fun when you try and do what you're supposed to do). Everything you do depends on your team and if they suck, or can't seem to work out that they should be disarming that station/capturing that flag then you are fucked no matter how good your skill is, but at-least you get to rack-up experience. It is best if your friends play the game, sadly none of mine do, but I still have a good time :( They all have CoD. LAG and when fighting teams that are so ridiculously well-planned that you can't beat them make me rage quit. During the halo reach beta there wasn't that many people playing hardcore on this game so I ended up fighting by myself on those occasion against the other team, and it was actually fun despite the odds. 
 
You also get these times when you are the attacker and you look at how many tickets/lives your team has left when you are nervous you are about to run out, and you see that it is still near the amount you started with, so you think everything's okay, then somehow your team manages to use up all those tickets in just a fifth of the time it took for you to get worried about running out beforehand. But those sorts of things are great in some respects because they make the game more exciting. I like working with a team, (even though I don't use a headset), everyone usually just knows what they have to do and you fulfill your role as Medic/Engineer/Soldier(assault)/Recon by using its' specialties to support your team. There is so many epic moments that you can encounter. You do get the occasional bad game but that's just life. 
 
Anyway I hope you read all that dribble because it may have been helpful somehow.

Hey, you like blowing shit up? Get BFBC2. There, done.

If I interpreted your words correctly, MW2 might be the better choice for you. If you don't have a lot of time to invest, and don't know anyone who plays BC2, MW2 might be a more lone-wolf experience that would appeal to you. 
 
Like with all first person shooters, there are people who are good, really good. MW2 will have the people who have all the perks, weapons etc. They will also know all the spots to camp, and where to boost and such. 
 
In BC2, there will be people who have become skilled with the weapons, and know the best postitions to provide crossfire for their team. They will also know the flow of the maps, and common strategies that the other team might use when attacking and defending. 
 
I would suggest getting a game-fly account, and then renting both games, and invest time in the multiplayer to see what you like best. 
 
But, BC2 is better. 
 
(sorry, just had to add that in there)

BC2 is kinda clunky but a blast when playing with friends. MW2 is fun when you aren't losing.

Actually, some of my best online experiences has been while playing BC2. That game is explosive as hell. There is always crazy action going down and shit gets really, really intense. I definitely recommend BC2. It's hard to explain how the experience in that game is, you just have to experience it to understand it. But if I were to use one word about it, INTENSE!

But, BC2 is better.  (sorry, just had to add that in there) "

Battlefield 2 is a little bit more realistic, and most of my friends say they don't really like it. I myself am a huge fan of it and think its better than MW2, BUT, I'm going to have to reccomend MW2 for you.

Easily Battlefield: Bad Company 2, while Modern Warfare 2 tops B:BC2 by grossing sales and popularity, B:BC2 provides quality over quantity. It's far more balanced and challenging, the maps are balanced as well and the destructible environments add a new layer if strategy by knowing how well to use cover. Modern Warfare 2 is an extremely unbalanced and uncompetitive multi-player experience, Battlefield: Bad Company 2 takes actual raw skill and challenge. 

battlefield bad company 2 = horrible single player, like half as good as modern warfare 2, it's just a cheap knock off at best. Multiplayer = better to most gamers on forums than modern warfare 2.