God of War: Ascension, Gears of War: Judgment and Fable III are the most disappointing for me, almost made me cry because of how bitterly sub-par they are compared to their predecessors. Although, none of them are actually bad games, GeoW:J & Fable 3 are above average and GoW:A is pretty good.
I had never played a MGS game before playing MGS4 but I didn't like the game at all, disappointing considering all the hype and acclaim. Splinter Cell: Double Agent was okay but such a disappointment after Splinter Cell: Chaos Theory. I didn't like GTA IV nearly as much as GTA San Andreas. Halo 3 & 4 aren't very good at all in terms of single player campaigns which was disappointing although I guess the great multiplayer which is obviously the main focus makes up for it.
To a lesser degree Uncharted 3, Gears of War 3, Bioshock Infinite, LittleBigPlanet 2, and Skyrim all disappointment me, even though they range from very good to amazing none of them lived up to their predecessors... well Skyrim was technically a better game than Oblivion but I much prefer Oblivion's OST & art-style. LBP2 was technically a better game than LBP1 but for some reason it didn't grip me the same way, didn't have that charm the first had, I bought it day 1 and hardly ever played it whereas I put 100s hours into the first game.







