My favorite games are The Legend of Zelda: Ocarina of Time, Chrono Trigger, Banjo-Kazooie, Tales of Symphonia, Mario 64, and Knights of the Old Republic, and Resident Evil 4.
It's difficult for me to find ones that I actually enjoy playing. Perhaps I'm just picky, lol. There are a few games I like, like Eternal Legacy, Evac, Plants VS Zombies (beat it though so I don't play it anymore), and Six Guns.
I miss playing Mass Effect (had it for the PC) and the plot + gameplay was really fun. Really loved the interactions with the aliens and epic plot (although the last one was really meh).
I hope Bioware comes out with a new game that has as complicated a universe as Mass Effect. Either that or I hope I can get it for the xbox, as I'd love to play all 3 again - but on console (I'm getting used to console gaming's merits).
Text based mmorpgs are my style of game though Final Fantasy 8 has to be the best game ever made (in my opinion) due to the size of area available, graphics and generally everything about it and it was all done on a PS1 which made it really stand out. FF13 onwards are just awful.
I love playing The Sims 3 and The Sims Medieval for PC. I have The Sims 3 for Nintendo GameCube as well (I play it using my Wii which is compatible with GameCube games) but you don't get all the options you get in game for the PC version. My favorite part of the game is decorating or building houses. I could spend days on decorating or building houses and not even play the people's lives!
Most any decently-done FPS...Still a huge fan of the original Quake I...here it is over 15 years since it came out & people are still creating new maps for it, some of them commercial quality...and with the source code available, the engine's been upgraded to take advantage of current capabilities....too much fun!