There are a lot of games that I don't care for but I wouldn't call them over-rated. The reason is simple - to call something over-rated is to imply that the game recieves it's accolades without merit and I can generally at least recognize that even if I don't care for it, it isn't necissarily a bad game.
Games in the category of "Everyone but me loved it":
Final Fantasy (any, but especially 7) - There simply isn't anything that draws me into the game. I hate the grind, I hate the system used in combat and the story is doled out in such tiny chunks (compared to gameplay) that I quickly exhaust my patience. It would seem that, given the tremendous popularity of the series (and it's imitators), that millions of people like the very things that annoy me.
Metal Gear Solid (any) - It's incredibly rare that I like stealth games, and MGS is perhaps my least favorite entry in the genre. That said, while I think the story is often rubbish, I find that I enjoy the movies more than the game. While I find no joy in playing the game myself, I have gotten at least a measure of pleasure watching other people play.
Halo (Multiplayer) - As one of the most popular online games ever, there is clearly quality that people like here. The slow pace of the game however has just never interested me, and if you combine that with the fact that the game mechanics allow badass players to be almost unkillable by cannon fodder such as myself I find that I rarely have any fun. While I'm sure I could grow to love the game if I played it long enough, I simply don't feel the need to as there are plenty of other multiplayer games to keep me interested.
Zelda (any since Link to the past) - I have to be honst, Zelda just isn't the game for me. I loved a Link to the Past and played it endlessly but it represents the only game in the genre to really reach me. I played Ocarina of Time (like everybody else) but found that the part of the game I actually really loved was the side quests. The actual dungeon portions were often so annoyingly difficult that I would shut off the console in disgust with myself after faiing at some task or searching vainly for clues for an hour. I finally gave up somewhere around the Water Temple.
Killzone 2 - The single player game annoyed me to no end. Multiplayer was even worse (who in god's name decided the class with the most health should also be the fastest AND carry the biggest weapons? Or worse, who decided that the sniper with the one shot kill doom cannon should also be able to turn invisble?), and the controller physically hurt me to use for long periods. I can see why other people would like it, but the game that sold me a PS3 was are sore dissapointment.