Arkham Asylum. This game got high scores almost everywhere, everyone I heard talking about it loves it, it seems to be a total nergasm to the entire gaming public. Personally, I was too bored to play about an hour after the Bane boss fight. And even getting there was a chore.
This partially stems from me not liking Batman much (and thus not getting all the jokes/memes about him being awesome). He's about as uninteresting a superhero as they come and the only thing that made the Batman franchise bearable so far were the villains. However, I found the AA version of the Joker downright annoying to endure, so that killed it for me even further.
I normally like 3rd person action adventure games. I adore the Sands of Time trilogy and the Legacy of Kain games, and I even played the crap out of God of War 1&2 this summer on my friend's PS2. However, AA didn't sit with me. The main character was sluggish and handled like a pregnant manatee. The combat was a fun when I first saw it, but as soon as the novelty wore off I found that it felt like a very long Quicktime event and was actually one of the low points of the game for me.
Detective Vision was a terrible idea. Making the player choose between getting important game info or seeing the nice graphics is about as dumb as they can make it. The whole thing could have been done in a far less invasive manner and it would've worked even better.
And the ever-present scavenger hunt for the Riddler crap was frustrating. It was a constant distraction from the game and not very fun, but if I didn't do it I felt like I was missing out, so it basically came down to a grind instead of enjoying the game.
In the end, it's a well crafted game with good visuals and a lot of features that aren't bad, but just didn't click with me and a protagonist/villain whom I dislike on the basis of personal taste. It isn't a badly made overrated crap like Oblivion or Crysis. It's a good game deserving of praise that I just didn't like.
EDIT: Oh and the cape! God I hated that cape! I get it, you've got a big black cape, can we move on now? Does it need to obscure half the screen and a good chunk of the action?