N64.
The Halo series.
PS3 untill Warhawk.

Death of the Dreamcast

the PS3 not being the last of Sony's consoles

I would say Nintendo selling RARE but it's nothing of value anymore..

Also Saint's Row 2 reviews

Super Smash Bros. Brawl... 6 and a half years of waiting turned into epic disappointment once I finally played it for myself.

1. Watching Sonic the Hedgehog become a shadow of his former self (pun intended).

2. Watching the platformer genre slowly die. On that note, hooray for Super Mario Galaxy.

3. Seeing Rare struggle to maintain it's former glory. At least they're still struggling.

Chrono Cross : it is an insult to Chrono Trigger.

No Quarian romance option in Mass Effect.

Oh hell no... disappointment... the only thing that disappointed me about this game was that someone stole my PS and I couldn't play it

1a. The collapse of the pinball industry. Stern just doesn't do it for me. I miss the gorgeous layouts of the Williams pins of the 90s.

1b. FMV. The 3DO was such an awesome piece of hardware, killed more by developer ineptitude at implementing emerging technology than by its capabilities head-to-head compared to all the other consoles of its day, plus the next five years too, the N64 notwithstanding.

Oddworld going 3d (the first two are some of the best games ever! worked perfectly 2d)....

PS3 having such an expensive launch...

Duke Nukem forever taking....well....forever to make!

PlayStation 3

Arrived late, games arrived more late, in Europe more more late, lot's of lies (power, compability, controllers, exclusives, online, etc), online didn't arrive at all.....

My biggest disappointment :(