In addition to what everyone else has said, you have to get Metal Gear Solid 4, sure its a few years old now but that game is AMAZING.  If you like film noir check out Heavy Rain which has some real intense moments but is more like an interactive movie. Like retro gaming?, try 3d Dot Heroes with lots of inside jokes and references to many classic RPGs. Pick up Shadow of the Colossus/Ico HD collection and Metal Gear Solid HD Collection too for some updated PS2 goodness.  Racing? Gran Turismo 5 nuff' said. I'll give a second thumbs up for Dead Nation which is easily one of the best PSN titles.

you're gonna play the ps3? are you a patient person? i hope so...

Guess everyone has their own tastes.

I say do not listen to this guy at all.

Heavy Rain is excellent, but not as good as Indigo Prophecy, and really short. I beat it in 1 sitting, and figured out the killer in the first 25% of the game (SPOILER!!! g*** ****h clue gave it away to me).

Metal Gear Solid 4......I can see why others like it, but I can't stand this franchise, and judging from what you said, I don't think you would particularly find this game good.

3D Dot Heros is meh.

However GT5 is an excellent sim, and Shadow of the Colossus/ICO collection is also a great place to start your quest on PS3. Actually I strongly reccommend the ICO Collection, I'll even bold it.

FLOWER!

FFXIII.

Retail:
Uncharted 1, 2 and 3
Metal Gear Solid 4: Guns of the Patriots
Ratchet and Clank Future: Tools of Destruction and A Crack in Time
LittleBigPlanet 1 and 2
Modnation Racers
Gran Turismo 5

PSN:
Costume Quest
WipeOut HD (plus Fury expansion)
PixelJunk Monsters
Super Stardust HD
Flower

PSOne Classics:
Final Fantasy VIII
Chrono Trigger
Chrono Cross
Vagrant Story
Suikoden
Breath of Fire IV

PSTwo Classics:
Odin Sphere
God Hand

Platformers you say? Ratchet and Clank Future games including Quest for Booty on PSN, LittleBigPlanet 2 and the Sly Collection.

RPG's? Demon and Dark Souls.

Thanks for all the suggestions guys so let me comment on them:

PS3:
Infamuos(Is there any demos for it? I must try it first)
Uncharted(I though about buying the second one but I decided to download the demo)
LBP 1 y 2(These interest me greatly but Im looking to get the GOTY version, is worth it?)
God of War(I downloaded the origins demo so let me see if I like it first)
Valkyria Chronicles(I dont know about an SRPG let me see more of it)
Demon/Dark Souls(Im no masochist so I think they are out)
Star Ocean 4(Lets wait for a pricedrop for this one, is pretty expensive here)
Ratchet&Clanck(They are my next purchases but lets try a demo first)
Sotc/Ico(Let the price drop before I look into them)
Gran Turismo(Im not interested, sim racers bore me to tears)
FFXIII(I dont know, let me think some more)
Batman Arkham(Im VERY interested in Asylum and Im waiting for a Goty City)
Heavy Rain(What is the gameplay like?)

PSN:
Flower(What is this about?)
Wipeout(I was never into F-Zero is this any different?)
Pixeljunk X(What are the differences between them?)
Dead Nation(Im not into zombies so I think I pass)
Costume Quest(What is this?)

PSClassics:
Final Fantasy(The only one that interest me are 5 and 9, are the versions up any good?)
Chrono(I have Trigger in my DS so thats a no and Cross interest me but I only have $6 in my account)
Breath of Fire(I was about to buy it but I decided to wait for some time)
Oddin Sphere(How is it? It looks interesting)

Sorry for the double post but is there any thread about PSN ID sharing? And also keep the suggestions coming Im open to any suggestion

What is your PSN ID?