Same as Adam really, The Sims 2 is the game I've been playing since it's release...
Some of my Favourites would be The MarioKart series, Crash bandicoot was always pretty good on the PS1 (PS2 versions are crap.) Then there's Oddworld, which is still pretty brilliant, GTA SA is good, Mario Platformers are great and Burnout is good.
I'd say my favourite retro is Oddworld, and my current favourite is either TS2 or any with an Italian plumber in it.
