The God of War series. I just rented the second one after giving up about an hour into the first one so I could try and catch up before I got God of War 3 (because EVERYONE was recommending it and playing it and such) and I'm trying so hard to like but just...ugh. Every single fucking enemy has to be hit twenty times before they go down and don't register as getting hit so they just keep attacking you as you chip away at their massive amounts of health. I just got to a point where literally twenty dog-things came at me and I have to hit them at least ten times EACH all the while dodging their attacks that can't be stopped. I'm a fairly skilled gamer, and it isn't difficult, it's just tedious as fuck.
Also, Halo. Its a great game, honestly, but after like, 4 months playing it day after day after day, I'm just so tired of it.