Okay. Let's see.
Final Fantasy III:
I mean the actual 3, not 6. I tried to like the game, I really did. Made it to the final boss, but damn did the game just not click. I think what disappointed me the most was that the DS version did nothing to really make the game feel less old past making the graphics hideous.
The World Ends With You:
I tried guys. I really did, but you hype trained this game so hard that it can't live up to expectations. Remember, if you won't shut up about a game, all you're doing is creating a Ubisoft/Watch_Dogs situation. If you like a game, hype in moderation.
Mario Galaxy:
I get that it's supposed to be the best Mario game we've seen in awhile, but I just felt like I was playing it because it was supposed to be fun. Nothing really stood out for me, and although I liked certain ideas, nothing made me go "this game is just amazing". I ended up not making it all the way to the end.
Legend of Zelda - Skyward Sword:
I tried to like this one as well, but boy did it just bore me the further in I got expecting the game to be fun. Certain parts were exciting at first, like the sword controls and flying through the sky, but it just became tiresome more than staying enticing.
Star Wars - Knights of the Old Republic 2:
Something about this game just didn't click with me. I played through from start to finish, but it just wasn't as good as the first game and I guess I was just really hoping it would do something to improve on the first game.
Kingdom Hearts 358/2 Days and Re: Coded:
I just lumped the DS entries together here. Boy did I really, really, really want these games to be enjoyable. I tried to hard to let them be fun. I beat 358/2 Days, and I made it far into Re: Coded, but both games ultimately just failed to do anything consistently right.
That's all that comes immediately to mind, some being entries from earlier in the list, but I'm sure I'll think of more eventually.