I can't remember when some of these came out, exactly, but they're probably close enough. Not all of these games are necessarily shit, but disappointment was certainly felt on a large scale towards them. In no particular order:
LittleBigPlanet
It was cute and fun for awhile, but the novelty wore off relatively quick. The multiplayer was downright unplayable for me and the level designer...well, I just don't like level designers, but apparently it also wasn't good by level-designer standards. I'll still pick it up and play through a level on a very rare occasion for mindless fluffy fun, though.
Final Fantasy XIII
I said that not all of the games on my list are shit, but this one sure is. I just loath the entire thing, aside from some of the characters. There is no fun to be had in this game, just a lot of running down long corridors and mashing auto-battle. The game's story also makes me want to bash my head against a wall, despite the fact that I have a very high tolerance for any Final Fantasy-style overly-dramatic silliness. I also disliked the asshole of a final boss, though that's just an egg in the cake.
Skyrim
Oh, Skyrim. So much potential, so little realization of it. Skyrim isn't a bad game by any means, but it wasn't what I was hoping for at all. The emphasis is too heavy on the action for my tastes and it felt extremely watered-down in its actual RPG elements. I can't take playing it for very long anymore; more often than not I simply choose to play Oblivion instead for a real Elder Scrolls fix.
Mirror's Edge
This game looked like it had a promising concept, though really I never would have played it if my sister hadn't bought it. As it turns out, running through linear levels in first-person just isn't my idea of fun.
inFamous 2
Before I go anywhere with this, let me just say I think inFamous 2 is a solid game and I enjoyed myself immensely playing it the first two times. Partly I'm putting it here to round off my list, but it did leave me with severe disappointments in certain areas. First of all, I wasn't pleased with the departure from the overall style that was established by the first inFamous. Yes, there were still comic book cutscenes and all that, but even though the graphics were undeniably better, i2 felt generic in comparison. Second, the game's karma didn't improve in the original's very one-dimensional approach at all. In fact it made it worse in some ways. I have a plethora of other nit-picks, mainly about the plot and execution of Cole MacGrath's character, but I could go on all day about this.
Mainly my discontent with inFamous 2 is that, in my unpopular opinion, it's not as good as the first game. Nevertheless there were still a lot of things I liked about it, particularly the game's vastly different and entirely satisfying Good and Evil endings. Plus it was just downright fun, which is what counts, so I'm a little unnecessarily harsh on the game at times.