Final Fantasy 6 is by far, the most over-rated Final Fantasy game, with #7 coming in at 2nd. FF7 was fun, but the overzealousness of its fans just makes me go WTF, same with those for FF6.
All Zelda games. Yes, all of them. I don't see the appeal of the series, and I had been completely disappointed in each that I attempted to play (thanks to my sister, who for some reason enjoys them).
Every single FPS game, especially in their online multiplayer portions. Everyone is a twitchy crackhead hopped up on cocaine.
And World of Warcraft, Starcraft 1&2, and Assassin's Creed, and God of War series.