Gears of War Battlefield 2 or 3 None of the COD games but MW 2 Halo 2 Halo Reach Most newer Mario games None of the Zelda games newer than OOT None of the Assassin's Creed games. (I refuse to support Ubisoft)
Probably tons of others. I don't play into community or fanboyish hype over flagship titles.
i've only tried the first game in these series and decided they're not for me god of war assassins creed infamous prototype halo ninja gaiden (love the nes ones, don't care for the new ones) devil may cry call of duty modern warfare hitman
also resident evil 6 (hated 4 and 5, nothing i've seen of 6 makes me want to play it) final fantasy XII and XIII-2 (hated X and X-2 so i skipped XII, tried XIII to see if i liked it any more than X or X-2 and hated it more than X and X-2) street fighter X tekken (hated the way capcom handled this game and the gem system sounded like crap)
there's probably others, but those are the first ones to come to mind