Metal Gear Solid (all) without a doubt.
I'm not a big gamer, or gamer at all these days.
I just never got a PS3 or kept up with it. I did buy an Xbox 360 in order to play the new GTA when it came out, but then sold the Xbox to get high lmao. Stupid.
But, I'm too broke to be able to get into it right now. But one game which was just... the richest and most stimulating experience ever was Metal Gear Solid.
The original (PS1) was amazing, the second (PS2) was incredible and the third (also PS2), Snake Eater was incredible too. They're just so well done, so packed, so crammed with plot and so well executed. And the graphics are always so ahead of their time and blow every other game on the console away.
I really can't wait to get a PS3 just to play the 4th. Pick up where I left off.