I want Everquest 2,despite never playing the first, or being much of an MMO player, and Diablo 3. Games I wanted bad in the past were Hellgate:London, Borderlands, and Red Alert 3 between the time of seeing it the cover of a magazine and reading actual the article.
What's funny is the difference between EQ and EQ2 is enormous. I still play EQ1, though I enjoyed the second.
There are only a few times I wanted a game this badly. Final Fantasy VII, Final Fantasy X, Final Fantasy XII, Final Fantasy XIII, Super Smash Bros. Brawl, and ...Bomberman 2 for the SNES (USA version).
I might be forgetting a few others. I often get hyped, but not often this badly.