Never played anything xbox exclusive as I've never owned (or ever plan to) an xbox. Never played the Mass Effect games, but seeing as how part 1 is apparently going to make its way to the PS3, I may just pick it up if they sell it in a cheap collection edition.
Haven't played any of the Bethesda games - Fallout, Elder Scrolls etc. - as the only reason I want to get frustrated at a game is because I suck at it, not because a dev is too cheap/lazy to work out the bugs.
"It would be the stupid comment about the a-bombs that the US dropped on Japan that is offensive."
Blaze Union; Tales of the World: Radiant Mythology; Most of the Fire Emblem series bar Shadow Dragon, Sacred Stones and whatever the 7th one was called; Smash Bros. Melee and Brawl; Paper Mario games beyond the first N64 one; Pokemon Coliseum; Most of the Madou Monogatari games bar Hanamaru Daiyouchi Enji; Final Fantasy XI
This covers a few of the ones I want to play. I haven't touched, nor do I ever want to play, any FPS or Sport game.
Honorable mention to the Zelda series that keeps trying to rope me into playing, only to be put down within minutes never to be looked at again. Tried most of them - overhyped tripe, that's all. Same with Metroid.
If you haven't played fallout 3/nv or oblivion/skyrim you really ought to experience it to some degree, Skyrim is probably the best place to start, but if your a cheapskate the earlier ones can be bought for almost nothing... Why not? Same deal with assassins creed games... They've got their ups and downs but you can grab one of them for basically no money... WHY NOT?
They say cooking is about experimenting, but no matter how many drugs I take it still tastes like crap...It needs more LSD, It doesn't taste loud enough yet.