There were several big ones:
Marvel vs. Capcom 3 - After 10 years of waiting, and having loved the older games in the series way back to the X-Men:COTA days, words couldn't describe how hype I was. Alas, what we got was a broken, charmless mess, that Capcom has done a shamelessly half-assed job of supporting post release. The most comprehensive effort they made to fix the game's problems was a $40 re-release, which they've batted away requests to patch over it's myriad flaws ever since.
Devil May Cry 4 - The barren wasteland of the PS3's early days, coupled with my undying love of DMC, let me gloss over a lot of the game's flaws when I first picked it up--a shit story even by DMC standards, forgettable characters, Dante being pushed aside for a more boring younger replacement, disgusting asset recycling, and so forth. By the time the reboot came out, I wasn't even that mad about it, as I'd come to accept that DMC4 was nothing special--a far cry from it's precessor, which I consider the best in the series and one of the best games on the PS2.
Tekken 6 - Tekken 1 was the reason I got a PS1 (along with my Dad being too cheap to pay for a Saturn); Tekken Tag was the reason I wanted a PS2. Hence I was super excited for Tekken 6, which was the main reason I wanted a PS3 as well. I was hoping to have an experience that, if not as much of a revelation as Tekken 1 was, would still be as big a step up as Tekken Tag (and as fun).
Instead, what we got was a snoozefest. The bound mechanic has turned the matches into a series of mini-combo videos, making it boring to watch and play in a way that none of the previous 6 games had been. The game also looked bad, mainly due to the jagged aliasing that the motion-blur did little to improve on. Tekken Tag 2 improved on both fronts, but for me, the magic of the series is gone--something I've never expected to say after playing the games for nearly 20 years. Hopefully, Tekken 7 will bring it back.
Aurum Ring 
Delano7 
Ocarinahero032
