So, I got a PS3 for christmas...

[Ieyke]

I'm leaving out a TON of multi-platform stuff because I dunno if it's on PC or not.

PSX Games:
*(The PSX/PSone had a LOT of RPGs. It was pretty much the golden age of RPGs.)
- Suikoden I (RPG)
- Suikoden II (pretty much the best RPG there is, but good luck obtaining a copy)
- MegaMan Classic Collection
- MegaMan X Collection (MegaMan X and X4 are the two best Megaman games)
- Castlevania:Symphony Of The Night (the absolute best Castlevania game, and just generally one of the best games ever made.)
- Chrono Trigger (RPG)
- Azure Dreams (hard to describe...roguelike, dungeoncrawl, RPG, Pokemon, dating sim, town building...)
- Thousand Arms (RPG)
- Alundra (RPG)
- Breath Of Fire IV (RPG)
- Lunar:Silver Star Story Complete (RPG)
- Lunar 2:Eternal Blue Complete (RPG)

PS2 Games:
- Okami HD (an Action Adventure masterpiece)
- Katamari Damacy
- Onimusha 2:Samurai's Destiny (it's the only Onimusha I played, so I dunno about Onimusha 1 and 3.)
- Suikoden III (The 3D Suikodens aren't as good as the 2D ones, but they're still good. Suikoden III is the best of the 3D ones.)
- Suikoden IV
- Suikoden V
- Dark Cloud 2
- Armored Core:Silent Line (Super customizable mechs that you do mercenary combat missions with. Presumably the PS3 Armored Core games could be better, but Silent Line was the best on PS2)


PS3 Games:
- Metal Gear Solid 4:Guns Of the Patriots (It's the first and only Metal Gear game I've ever played. It single-handedly hooked me on the series....assuming I ever get the time to play the rest.)
- Uncharted 3rake's Deception
- Journey

================================================================

I'd recommend these, but you already have them or don't want fighting games:
- The God of War collection(which has the main 3 and 2 of the side games).
- Unchartedrake's Fortune
- Uncharted 2:Among Thieves
- Xenogears
- Chrono Cross
- Final Fantasy Tactics (I would suggest the remake - Final Fantasy Tactics:War Of The Lions - for some added characters, and extra job class, better localization, and beautiful cut scenes, but the original is still fantastic. Either way, FFT is EASILY the best Final Fantasy game)
- ICO/SotC Collection
- Darkstalkers Resurrection
- Ultimate Marvel VS Capcom 3

Games that I'm interested in which have an incredibly solid reputation:
- Ni no Kuni: Wrath of the White Witch
- The Last Of Us

 

[Frezzato]

Theres also the HD PS2 Ratchet and Clanks available for download and the first 3 have retail compilation release.
And Into the Nexus is good. Short but sweet. And it's only $30 for retail which includes Quest for Booty for free!

I'm disappointed that I missed that! I didn't even see the inclusion of Quest for Booty until I zoomed in on the box image on Amazon.

*EDIT* I'm going to second (or third) the suggestion for Journey. Despite the fact that it lasts only maybe 4 hours, it's seriously worth it. Not that I love That Game Company's other two games as much as Journey, but you can get all three for just under $20. Unfortunately, even though you get a disc they're apparently just codes for download.

 

[COMaestro]

The Last of Us is a game you should definitely look into. It seems to really be a love it or hate it type game, but I found it to be excellent.

Also highly recommend the Metal Gear Solid legacy collection. As someone stated above, definitely play them in order, as the play controls get better as the series goes on and it's much easier to adapt to added mechanics (like a movable camera) rather than having them taken away.

Okami is a wonderful Zelda-style game with a beautiful art style. I've only played the PS2 version, but you may as well go with the HD re-release.

Having played the Vita release of Persona 4 for somewhere between 250-300 hours, I can highly recommend it, though I haven't played any of the other Persona games yet to comment on them, though I have purchased 2 and 3.

I greatly enjoyed Castlevania: Lords of Shadow, and the sequel is due out early this year, so now would be a good time to jump in. They recently released a version that comes with an HD remaster of Mirror of Fate, which was a 3DS release which fills in more story between LoS and the upcoming sequel, so if you are interested you may as well get that version. And as leyke stated above, Caslevania: Symphony of the Night is absolutely fantastic and you owe it to yourself to play it if you get any enjoyment out of Metroidvania gameplay.

For the PS2, I adored Zone of the Enders, and its sequel ZotE: the Second Runner. There's an HD version for the PS3 which you can probably find for about $15 nowadays, though I have no idea regarding its quality.

Ultimately there are a ton of games that are worth playing when you're looking at the entire Playstation library of games. I could probably recommend stuff all day, but I'm going to stop here. Sounds like you already have plenty of games on your plate already. Never a bad thing

 

[Fiad]

Kingdom Hearts 1 and 2 for the ps2. Some of my all time favorite games.

 

[Brotha Desmond]

SNIP

A few good RPGS on PS 1+2 are anything with the Shin Megami Tensei banner, especially the Persona titles. If you don't mind 2D anime based fighter then I'd have to say Dragon Ball Z Budokai 2 for the PS2, which is my favorite of the original Budokai games.

For PS3 I recommend the InFamous games, and Hatsune Miku Project Diva F (a good rhythm game).

 

[Tanis]

I'd suggest getting PSN+, it's well worth it.

PS3 Games (Physical):
3D Dot Game Heroes - It's like a parody/homage to classic Zelda games.

Batman: Arkham City - I like it more than AA.

Blur - A sort of 'adult' Mario Kart.

Civilization: Revolution - A streamlined version of the Civ series, that plays rather well.

Darksiders II - Pretty damn good action/puzzle game, so much better than the first one it also feels like a totally new franchise.

Demon's Souls & Dark Souls - Games that will grow hair on your testis/ovaries.

Deus Ex: Human Revolution - Surprisingly good FPS with stealth elements, but the boss fight do feel out of place.

Dishonored - First Person Stealth/action game, reminds me of 'Thief light'.

Disgaea 4 & D2 - Both fantastic SRPGs.

Dragon's Crown - One of the best games to come out in a decade, a spiritual successor to the likes of Golden Axe and Double Dragon.

Dragon's Dogma: Dark Arisen - Action RPG that was improved/fixed by a rather decent DLC pack.

Dragon Age: Origins - It's sort of like Baulder's Gate, with less disc swapping.

EDF: Insect Armageddon - A 3rd person shooter set in a sort of cheesy Japan Kajin film setting.

Fallout: New Vegas - Because FO3 was, and still is, shit.

Folklore - Surprisingly enjoyable 3rd person action game.

God of War HD Collection - There's actually two of these, one is GoW 1/2 and the other are the PSP games. Both are worth getting if you like the series.

Heavy Rain - Interesting idea, poor execution, but a solid experience nonetheless.

Journey Collector's Edition - Contains Flower, Flow, Journey, and a free 1 mouth PSN+ voucher. All great things.

Katamari Forever - It's a Katamari game, and it's fun. Roll shit up, because, reasons.

Ni No Kuni - One of the best JRPGs in probably the past DECADE.

Killzone Trilogy - Solid FPS series, worth at least a rental to play though the three.

Kingdom's of Amalur: Reckoning - Surprisingly good open world RPG, with combat that's really enjoyable.

ModNations: Racers - It's a kart game, and it's fun, but you might like LBP Racers more.

Persona 4: Arena - Made by the Guilty Gear folks, with Persona characters, nuff said.

Portal 2 - 1st Person Puzzle game.

Ratchet & Clank HD Collection - Has the first three games in improved graphics, still fun games after all this time.

Rayman: Origins - Amazing platformer, don't forget about the sequel which improves upon it.

Red Faction: Guerrilla - GTA on Mars, with more blowing shit up.

Sleeping Dogs - GTA in Hong Kong, with less guns and more melee weapons.

SSX - Return of one of the few enjoyable sports series.

Transformers: War/Fall of Cybertron - Solid 3rd Person Shooter/action series.

Tomb Raider - Reboot to the classic series that does everything right, best TB game in years.

Twisted Metal - Car carnage, probably the best TM since black/2.

Ultimate MvC3 - Great fighter.

Valkyria Chronicles - Fantastic SRPG with an engaging story and OST.

Vanquish - 3rd person action/shooter in an over the top setting.

Warhammer 40k: Space Marine - Surprisingly good 3rd person action/shooter set in the WH40k universe.

Yakuza 4 - 4>3.

Zone of the Enders HD Collection - One of the best mecha games of last gen, made better looking for the new gen.

 

[Dalisclock]

-Chrono Cross

Not so fast! it isn't strictly necessary, but I highly recommend you try Chrono Trigger first. They take place in the same universe, so it'll certainly help you understand the world. Plus, I'd recommend Chrono Trigger to every man, woman and child on the planet. It truly is excellent.

I've already played Chrono Trigger, which is why I got Cross.