Prince of Persia (the one with Elika as the female character), great game, my first platinum too. The other ones are God of War Collection and GoWIII, of course, U: DF and U2:AT. Too bad that R&C:ToD doesn't have trophies, i never finished that game. R&C:ACiT was pretty fun to play for Platinum.
IMO, people don't count "kid games" as legitimate platinum-worthy are wrong! While the games might not be fun/polished/balanced, but some of trophies are equally anal. I gave up the platinum on G-Force, it's freaking insane!
I happen to platinum Planet 51, people said it was easy platinum. Well, good luck! That kids' game is freaking insane to plat... Partly because it was broken and mostly because it's quite anal.
Most fun and enjoyed platinum (hard, but ultimately rewarding):
GoW Collection (flawless column climbing and the Challenges)
GoW III (aMAZEd and annoying Zeus, or even Hades)
PoP (annoying complete combo perfectionist, the Epilogue is more difficult, i completed that too, 100%

)
U: DF (crushing mode

()
U2:AT (again Crushing mode, but there's a cheat)
R&C:ACiT (blaster runs hot, annoying... but it's a lot easier on EASY, duh)
Heavy Rain (super sweet to plat, love it... Perfect Crime is a bitch though and i hate to kill Madison a number of time on purpose

()
SAW (i'm actually one of the few liked the game, thank goodness that you don't need to beat it on hardcore mode, i'm not sure how hard is it, but the later puzzles require more time and thinking)
Dante's Inferno (easy to plat and fairly fun till the end... i haven't play the DLC yet).
By far the easiest to platinum are (somewhat boring, but satisfying platties):
Hannah Montana
Trivial Pursuit
Up
Where the Wild Things Are
Mediocre (not very fun, but satisfying to plat):
Saga Collection (US and EU versions have different trophy folders, so technically you can have two platinum trophies of the same game)
Terminator Salvation (it's a quite broken game, not hard, but broken game)
Planet 51 (anal anal anal - AI in the last racing task cheats like hell and then there's that Chuck can't make mistake mission, sigh, worse than Kratos' Challenges)
Ice Age DoD (anal anal anal - the egg rolling is rigged, the timer goes on while the game loads! You will need perfection to achieve the goal)
Mundane platinum, but i like it:
Dynasty Empire (sigh, so repetitive... thank goodness that you don't have to all of the objectives)
Star Wars FU - with all of the DLCs too (broken

()
Star Wars CW RH (so broken

()
Games i haven't plat yet, but will one day:
Darksiders (good game, still haven't finish it yet)
Bayonetta (also a good game, but i suck at Witch Time)
inFamous (collecting shards and stunts, i hate those)
Tomb Raider Underworld (collecting treasures, sigh, i hate those)
Legends of WM (almost there, the final gold trophy is quite anal)
Games I probably will not plat:
Warhawk
KZ2
R2
SFIV
Burnout Paradise (hate on-line trophies)
Like i've said before, trophies are more addictive than achievements simply because of the Platinum Trophy! 100% completion in achievement is 1000 points, but in trophy terms, it's almost like extra reward for 100%. So, ten platinum trophies is pretty much 10,000 achievement points.
As for leveling up in the PSN community, man, it gets really tough after level 15... My goal is level 20, but it looks like there's a lot of work ahead :lol: