Castlevania Harmony of Despair. Here's my review.

Castlevania Harmony of Despair is a fu**ing joke. 1/10.

Other M

FF12, FF13, ME3

Paper Mario: Sticker Star and Halo 3 ODST

In terms of high expectations not met, Mass Effect 3 sticks out as the most recent culprit. I'm attempting to play it again currently but I can't see myself sticking with it.

Agreed.

GTA4 was a huge let down after SA.
They made the game smaller!!!

Mario Galaxy too. I wanted my 3D Mario exploration and i got a otherwise fantastic 2.5D linear experience.

Stronghold 3, Fable 3, SOCOM 4, GTA V etc.

Metroid: Other M
New Super Mario Bros
Halo 4
Ninja Gaiden 3
Uncharted
Grand Theft Auto IV
Killzone 2

Marvel Ultimate Alliance 2. The first MUA game was simple but had a long 12 hour campaign. 2 was at max 5 hours long. I cleared it in 2 hours by spaming certain character moves. The game had a ton of characters. But 20+ where stuck as NPC for no reason. The story was great. But with the exclusive version characters, and really short campaign. It became boring fast.

Ultimate Marvel VS Capcom 3 ruined the series just because they wasted the vanilla version less than a year later. I paid $80 for the collectors edition. I'd have to pay another $40 that were promised for my version. They go blame this nonsense on the earthquake. Worst excuse ever.

Uncharted 3 wasn't all that good. Mainly the MP section of it. UC3 was my first UC game. But I have watched the first two before. 3 felt like something was lacking in the story. it wasn't short. But had some weird issues in levels. The MP protion is just horrible. Guns are either overpowered. Or the lag just ruins the game. Had to give up on most of the modes that don't involve co-op.

SKyward Sword. Between Fi spam and the repeated use of the balloon sword boss. Made me not want to finish it.