I have platinum trophies for both Uncharted 2 and God of War 3. I have to really like the game to go for it.

I've got platinums in Burnout Paradise, Uncharted 2, Ratchet and Clank: A Crack in Time, Assassin's Creed II, and Borderlands. 
 
I'm fairly close in Just Cause 2, Infamous, and Fallout 3 so I'll probably get the platinums when I eventually go back to them.  Also, maybe Red Dead Redemption and MW2, but those will require a little bit more work and a Spec Ops partner.

I have about 6, but I'm forever screwed on a few.  
 
Honestly, achievements and trophies were fun to chase for a while, but it became clear that some are not worth it. One trophy away from the Platinum on BioShock 2 (one of many examples) but I cannot sit through another 3 more hours of the multiplayer. It was fun at first, but I got so burned out on that game. 
 
When trophies stop being fun, I just stop. Why put yourself through hell to get something that will never be meaningful?

I've got 5:  Demon's Souls, Heavy Rain, Infamous, Uncharted 1 and 2 (no multiplayer trophies though).   Also, Flower doesn't have a platinum but i finished that as well.

" I have about 6, but I'm forever screwed on a few.   Honestly, achievements and trophies were fun to chase for a while, but it became clear that some are not worth it. One trophy away from the Platinum on BioShock 2 (one of many examples) but I cannot sit through another 3 more hours of the multiplayer. It was fun at first, but I got so burned out on that game.  When trophies stop being fun, I just stop. Why put yourself through hell to get something that will never be meaningful? "

Hahahaha! Just like inFAMOUS! Playing that on hard is like taking candy from a baby. I guess I'll go for the Star Wars platinum then also since it's not hard. Go platinum trophies! The Sly Collection trophies look really easy also. Maybe the easiest.

They're not a waste. Adds something to do with the game after you've more or less finished it, you know?

Got 2 platinum trophies, Assassins Creed 2 and Batman: Arkham Asylum. Was working on inFamous but got sick off my second playthrough after getting to the 3rd world on Hard(or whatever the hardest difficulty was required), was also going for platinum on Fallout  3 but I think I played the CD to death cause it started to crash on me :P.
 
And no I don't think they're a waste, cause some games are really fun to play for platinum like AC2 and Batman: AA(especially this game).

I got my first two yesterday WAW and Uncharted 2.

" I got my first two yesterday WAW and Uncharted 2. "

I have platinums in Fallout 3 and Borderlands. Currently trying for Fallout New Vegas but game slowdowns and lockups really make it hard to play for long stretches of time. Currently at 40% on trophies I think. 
 
I wish I could make an attempt at more platinum trophies but  I don't really have enough time to get better at the games I have.

I only care about those when I can get all other trophies in the single play such as fallout 3 or inFamous. Currently working on the AC:B, hopefully i can get those multiplayer ones easy

For Platinums I have... Uncharted 2, Borderlands, Sly Cooper 1 (about to get Sly Cooper 2's)

I'm lv 10 with 605 trophies and 2 platinums in Assassin's Creed 2 and inFAMOUS. I usually only go for the platinum if it's fun to do so or it's a situation where I'm like one or two trophies away. Usually though, when I finish the narrative of a game I move on to another game.

Yeah, I think they are a waste. I just don't have the time to finish a game completely, I even have troubles just finishing most games at this point.

I have four:
 
Uncharted
Uncharted 2
Sly Cooper 1 (will be getting the rest in the collection eventually)
Yakuza 3
 
Yes, I have a platinum in Yakuza 3.
 
I got all the shards in Infamous, but I think the 100% karma trophy stopped me from planting because I have no-way to level-up anymore.
I was thinking of getting a platinum in Final Fantasy XIII, I still might, but the level-grinding seems really ridiculous. This is coming from someone who S-Ranked both Lost Odyssey and Resonance of Fate. :/

Burnout, inFamous, and Uncharted! All of them were worth it. Great games. =)

I have five:
 
inFamous
Assassin's Creed II
God of War I&2
Prince of Persia(2008)

I have 12 and I am Level 12: 
Fallout 3 - 3 playthroughs, each > 100 hours
Dead Space - good game, but not very memorable
Unreal Tournament III - this was a grind, but fun playing w/ keyboard and mouse
Call of Duty: World at War - my favorite CoD, but ridiculous grenade spamming
Bionic Commando - no manual save and no back-tracking
God of War - amazing, but challenge rooms sucked
God of War II - exceptional
Uncharted: Drake's Fortune - overrated
Sonic's Ultimate Genesis Collection - hemorrhages trophies
inFAMOUS - best PS3 exclusive (after MGS4 of course)
Assassin's Creed II - beautiful game but easy
Borderlands - addictive gameplay, but awful story
 
Most Anticipated Games:
inFAMOUS 2, Metal Gear Solid: Rising, Resistance 3, The Elder Scrolls V: Skyrim, Batman: Arkham City, Agent, Mass Effect 2 & 3,  Killzone 3, Rage, L.A. Noire, Mortal Kombat, Dead Space 2, Portal 2.

Got about 8 I think, right now I've got 1 full playthrough and about 4 chapters remaining on my current playthough to get the Uncharted 2 platinum.
 
I usually use getting a platinum as my being done with a game, and like to get it before I move on to another. Except I don't care for multiplayer trophies at all, so games with those I'll just get SP trophies and move on.

Killzone 2 and GOW3. That's the only two games I liked enough to replay more than 3 times...

I like getting trophies, but like a lot of you, I only go for them in the games I really like. 
 
Click my mini bio to see my trophy card. 
 
My 12 platinums: 
Mirror's Edge (definitely the hardest one of the bunch, with all those speed runs.)
Fallout 3
Uncharted
Uncharted 2 
X-Men Origins: Wolverine 
Borderlands 
Trine 
Batman: Arkham Asylum 
Burnout Paradise 
Battlefield: Bad Company 2 
Heavy Rain 
Assassin's Creed 2
 
I actually tried to get the Dead Space platinum as well, but I couldn't get that asteroid shooting trophy. You kids and your fast reaction times!

If they had the hooks for APIs, like the Giant Bomb achievement system, I would care. I didn't care about Steam achievements until Giant Bomb added them.  
 
You hear me, Sony? Let people use yo shit.

I currently have: 61 Platinums with a level 20 Trophy lvl

psn: negraru96

If you guys need help, join the Ps3t community!

@negraru96: WTF is this?

I only have 1 for Sly Cooper, it was extremely easy and just involved playing the game.

I got close with a few games though. I found all the blast shards in inFamous and did most of the extra stuff, I just need to finish my second playthrough.

I also did a lot of the trophies in Uncharted 2 but can't be assed playing through a third time and sitting there with a guide to get the treasures.

And all the riddles in Arkham Asylum and Arkham City - the only thing preventing me from getting platinums is playing games more than once.

I got 46 .