Try Mass Effect 3. Much more disappointing. And no, not because of the ending.

When I bought this game, I knew exactly what I was getting... so it wasn't disappointing to me...

Ever tried the Battle Colluseum?

Battle Revolution is indeed a big disappointment. It had all the tools to be Pokemon Stadium 3, Instead, if you don't own a DS with either Diamond or Pearl, the game becomes a shell of itself. And even if you have those games, its still not great.

I'd prefer a game that mixes up Colloseum (albeit if they make it more like the handheld games) and Stadium. That would be really cool, but unless Nintendo is really strapping for cash, they won't make that.

As for what game I was most disappointed by? Probably Epic Mickey, but I've revisited that game and have made amends with it. My expectation were incredibly high for that game

That was sad :(

War Z. All I need to say.

I give you right that the game is really disappointing, but of all time? I don't think so. Guild wars 2 was a really great disappointing, you got promised a lot of things but only get the boring stuff. Actually in the last few years there have been A LOT of disappointing games, and many of them just like Pokemon BR. Bring me back to the 1980-200X where GOOD games was made T_T

I think every person has their own unique most disappointing game, much like everyone has their own unique favorite game. It's unfortunate that Nintendo botched this opportunity; I guess the only solace is that it looks pretty.

Fable 2.....enough said.

I wish this game was more like Pokemon Stadium... Those were the days.