In order:

1. Final Fantasy XIII- The worst game I've ever completed. Considering the history of quality the previous 12 games had, this was a horrible insult to the JRPG genre.
2. GTAIV- Compare to San Andreas... nearly everything is inferior.
3. Duke Nukem Forever- I wasn't expecting much by the time it came out, but remembering playing Duke 3D in the 90s... such a shame to see the series go out like this.
4. FEAR 3- and 2 to some degree. The series just kept going downhill.
5. Dragon Age II- Dumbed down combat, reused assets, slow to start, removal of races and generally inferior to Origins. Not a bad game and the story is fairly good but disappointed overall.

Killzone 3's single player was EPIC! but the story was crap.

I enjoyed Skyward Sword more than Twilight Princess


I must go with Other M...what a turd ! I´m not even talking about the Story, the production values were through the roof, the cg cutscenes look amazing and it has great graphics (from a technical standpoint)...the Rest ?
Falls flat on it´s face, shit leveldesign, shitty gameplay (fucking auto aim in a Metroid game? Pointing at the screen for first person mode)...was there even music (after the outstanding soundtracks of the 3 Primes)...enemy design ? A far cry from the Primes and even the earlier Metroids ! Controls ? Yeah it is a great idea to use a D-Pad in a 3D environment...it´s not like the N64 ever existed...

Bah !!! I hope that this gameplay style for Metroid will stay dead and we will go back to Sidescrollers and First Person Adventures!

Biggest disappointment was Skyward Sword. Other M was garbage, but I had zero expectations so it was in line with my expectations.

RE6 was just terrible. But, so was 5. A lot of the super hyped games were crap this gen

Bioshock 1 , infinite . the most overrated games ever

The online "With Friends" is more than fine. It's actually much better than the fixed settings found in games like SFIV.

GTA 4. The series was getting better and better with every installment then, all of a sudden, BAM!, Rockstar dropped a stinking turd.

What is everyones problem with Metroid Other M?
I thought the game was good, I enjoyed it more than GTA 4.

HD JRPG outside of Mistwalker and Tales team

Bioware post EA

MGS4

Uncharted 1 after beating Uncharted 2 and listening to fans

Ninja Gaiden 3 has got to be it.  Close 2nd would be Aliens: Colonial Marines.  That game should not have been green-lighted to ship.

Oh this too, Uncharted 2 was very enjoyable (not as earth shattering as some want you to believe, but very enjoyable as a shallow-hollywood-movie-game)

The first ? ...urgh...