Spot on with all 3, I think you'll find.

Dishonored (scenery is boring, gameplay is boring, story is boring)

Red Dead Redemption (couldn't get into it)

Bioshock (seriously, this game sucks)

Fallout New Vegas (loved FO3, but seemed the same only boring. Stopped after 5-10 hours)

Its quite funny seeing people say that ME3 "ruined" their ME1 and 2 experiences because all of the apparent work that they put in to the franchise got pissed on by the 10 minute ME3 ending they didn't like...

At least you got to play with that turd (just like Duke).

GTA IV
Crackdown 2
Mass Effect 2/3
Gears of War 2 multiplayer
Last of Us singleplayer

Overall though, I'd probably go SOCOM 4

Spore. I spent so many hours with the creature creator because it was amazing and that got me super hyped for the game which ended being a big pile of nothing.

God of War: Ascension. It was more of the same and wasn't as epic as previous titles.

Star Wars The Old Republic, even though I have not expected to get my KotOR 3 fix from it, it was still so dissapointing it wasn't a different game.

Pokémon Black/White - After taking like a 1 1/2 half year break from the series I ended up being uninterested in the series again. Lets see what X/Y has in store for us.

GTA IV - Story was somewhat enjoyable but the world was not and a big step down from previous titles.

M&L PiT - Yeah, the babies pissed me off and made the game worse than it had to be. The Shroobs didn't help either, as they are amongs the worst villains in history of gaming.

Yoshi's Island DS - Yeah, the babies pissed me off here too and this time even more screams, poor level design and it felt like a chore.

Dishonored: kind of harsh to call this most dissapointing ... it was not nearly as good as it was hyped to be, but it is still enjoyable ... also it has gotten a lot of DLC support which is very nice.

Red Dead Redemption: I don't think anyone thought this was disappointing. Sorry it was not for you.

Bioshock: It is one of the most overrated games of this generation, but I wouldn't say it is dissapointing.

Fallout New Vegas: No argument to this. I stopped after 5 hours too. Was like a Diet Fallout 3. Same as Fallout 3, yet all of the fun and flavor was removed, and a bunch of glitches and broken mechanics were added.

One more game to consider ...

Brink: Nothing good can be said of this game. What a piece of garbage. Probably the laggiest and most glitch filled experience I have ever had in a game. Even when it worked properly though, it was not a fun game.