Just getting this thread started to let it cook for a moment so I can have a decent amount of recommendations for the poll.

As far as my favorite PS3 games, 

Infamous 2, Ratchet & Clank Future (all of them tbh), Uncharted 2, Bioshock, Portal 2, LittleBigPlanet 2, Rock Band, Borderlands 2, and a game that I'm probably the only one that remembers called 3D Dot Game Heroes. 

Currently, the poll schedule looks like this: 

Next Poll: Most Anticipated October Release
Following Poll: Best PS3 Game
After That: PSP or PSP/Vita depending on the response

The Last of Us is my pick, bought the system to play this game, was not disappointed.

Really enjoyed Uncharted 2 and 3 as well and liked Quantic dreams adventure games Heavy Rain and Beyond: two souls.

Ratchet & Clank a Crack in Time!, Tomb Raider (2013), Modnation Racers, LittleBigPlanet 2, Wipeout HD Fury, GTA V, Uncharted: Drake's Fortune

Objectively, I'd say GTA5 or TLOU. Subjectively, I'd go with Uncharted 2.

Demon’s Souls for me, followed by God of War III and Uncharted 2.

Demon, full stop

Oh that's a tough one. There are many I wanna say because of nostalgia but I have to go with GTA5, I beat that game 5 times and it never gets old, it's aged emaculately and is just a perfect game.

God of War 3, Resistance 2, and Uncharted 2 were my personal faves.

Uncharted 2, it was my first platinum. I don't platinum many games or replay many non Nintendo games but I've played Uncharted 2 at least 5 times.

For the next three consoles the answer is Persona 5.

Since I played it on PS3 originally that's easily my choice.