Call of Duty Modern Warfare.  I had the original call of duty for pc. The multiplayer was fast paced, action packed, and not completely sniper dominated.  In fact it was more like counter strike to me.  Modern Warfare became a snipers paradise, step out of aa building, killed, respawn, killed.  It changed the way that the game was played completely, ruining it for me.  At least there was Halo, but from the looks of it, 343 is ruining that.

Sega and BioWare's Sonic Chronicles: The Dark Brotherhood. The debate here is whether it just proves that Sonic can contaminate even the best of gaming companies, or that BioWare are less competent than people imagine them to be.

Likely a little of both.

I felt in quite a similar way for this game- I can see why some people would enjoy it, but it wasn't anything special for me

I'm fairly good at judging a game just by looking at it and setting my expectations at the appropriate level, so I'm rarely severely disappointed in anything. However, that also means I'm not positively surprised that often either, which is... draining.

But there are a few games that managed to pass miles beneath my expectations. Namely, Super Scribblenauts, Kirby's Epic Yarn, Spyro: Enter the Dragonfly and Metal Slug 5.

Out of those four, the only one that was actually almost, nearly, quarterway to being "not shit" was Metal Slug 5, but I also really had high expectations for it, so I think Metal Slug 5 is the most disappointing game I've owned so far.

Too many to name, but I'll list my top 5.

1. Devil May Cry 2 - The first game had great gameplay and was challenging, but the second one was incredibly easy. Dante Must Die mode in DMC2 is easier than the normal mode of DMC1. Boss battles were terrible; you can easily spam bullets/rockets during a boss battles. Also, the weapon selection was terrible.  The only good thing about the game was the soundtrack.

http://www.youtube.com/watch?v=WTqjpFWP20w

2. Yoshi's Story - I loved Yoshi's Island; it's one of my favorite games of all time. And I was expecting Yoshi's Story to be just like YI, but nope, it was entirely different. Too easy, too short, having to eat 30 fruits to end a level was lame, and the songs the Yoshis would sing after beating a level was embarrasing to hear.

3. Metal Gear Solid 4 - I did a whole thread on it. gamrconnect.vgchartz.com/thread.php?id=139962

4. Uncharted 3 - I loved the second game, but I found the third one boring. It's too scripted. You don't even get to shoot anyone in the first hour or so. Speaking of shooting, the aiming and shooting mechanics were terrible. I don't remember them being this bad in U2. There are too many chase/running away sequences, like 11 of them I think. It's an overkill and gets annoying after a while. Hated that they forced melee combat numerous times. Melee isn't very good at all and pales in comparison to Batman. Bonuses and tweaks were absent which lowered the replay value. Desert scene was incredibly dull; all they had you do there was walk for fifteen minutes until it was over. BORING! End boss 'fight' was laughably bad; you didn't even have to do anything, just counter his attacks. And it was lazy on ND's part to end the game the same way U2 ended - "falling city."

5. Grand Theft Auto 4 - There was a lack of variety in missions which made the game repetitive and boring. Driving was terrible. Gameplay was too clunky. Cell phone system was annoying. If you declined a call, your relationship goes down, and if you turned off your cell phone, you couldn't progress because some missions are given to you through your cell phone.

From my Wii collection:

Final Fantasy: Crystal Chronicles: The Crystal Bearers - As pretty as it is, it's a complete mess. The fundemental gameplay is broken and then all sorts of things are half-assed to compensate for it's brokenness. I really wanted to like this game and there are lots to like (story/graphics/some gameplay) but the more I played the more I hated it.

Lara Croft: Underworld - While Legend and Anniversary are amongst my favorites this one fails to entice me to keep playing. Boring. Plus the (Wii) controls were great (albiet tacked on) in Anniversary, completed changed for Underworld for the worse. Huh? Why? Plus game breaking bug. Very disappointing.

Anything from Sega: NiGHTS, Sonic The Secret Rings, Mario & Sonic at the Olympics, Sonic & Sega Superstars Tennis, etc. Lovely cut-scenes. Boring gameplay. Learn from Nintendo dudes!! Gameplay first!

360:

BioShock: Found it boring as hell.

Dragon's Age Origins: Loved Buldar's Gate which this was suppose to be a spiritual successor too but on 360 the isometric view is removed which removes much strategy and turns it into a poor action RPG.  Hated it.

Mass Effect: Loved the story, hated the fighting gameplay.  Prefer Knights of the Old Republic to this any day gameplay-wise.

Burnout Paradise:  WTF?  Huge Burnout fan on GC/PS2 but this one had too much unnecessary crap, way too much advertising. 

Kinect - With the exception of the excellent Dance Central, there's nothing on Kinect I'd want to play.  It's not responsive enough.  And Really? I have to stand?  Always? F--- that.

360 in general.

GT 64, i was really hyped about it, expected something like GT and it was more like Sega touring car at 10 fps, the game was premium crap.
I was a bit disappointed with RE3 also, not a bad game by any means.
More recently GT5 hyped me a lot cause GT on PS2 is my favourite racing sim by far, i expected the game to be revolutionary and i just got a GT4 with slightly upgraded mechanics, hi res graphics, more cars/tracks , an absolutely horrendous interface and the total destruction of the GT mode experience..............its a good game but nowhere near the masterpiece i was expecting.
GTA4 also, is not on par with San Andreas which is highly disappointing.
Mario Galaxy was also a bit disappointing after the EXCELLENT Super Mario sunshine, still a very good game but lost the exploration thing 64 and sunshine had.
Modern wrpgs and fps are all of them equally overhyped and disappointing also...........

Bullet Proof, I was a big 50 cent fan at the time and I thought it was going to be like GTA, I just ended up listening to the music than playing the game.

Rudolph the Red Nosed Reindeer for the Wii. Talk about the waste of a license. For me to dump a game and not worry abut the $17 loss I was taking,, you know it must be really bad.,

Mike from Morgantown

So many Gamecube games to choose from... Mario Sunshine, Double Dash, Wind Waker, Starfox Adventures, Eternal Darkness, etc, etc, etc.

I'd be tempted to say Nintendo's entire GC output apart from Metroid Prime and maybe Melee.

As for this generation, LA Noire stands out above all other contenders.