There are some games that deserve sequels, you know? To start the list:

Conker's Bad Fur Day

I haven't played this game yet (I will when I'm 16 though), but I've watched my brother play parts of it, and it looks insanely funny and fun. Unfortunately, I don't think we're going to get a sequel to this game because Rare doesn't focus on platforming anymore.

Sonic Heroes

Unlike most of the gimmicky Sonic games, Heroes had a gimmick that actually worked fairly well. The tag-team mechanics were actually fun, and you don't dread playing as the Sonic characters for once. If they made a sequel to this game, I think they should allow you to customize your team however you want to so you aren't forced to play as characters you don't want to, and so you don't have to play through the game four times...

Super Mario Sunshine

Super Mario Sunshine was a game that had so much un-touched potential it wasn't even funny. If a sequel were to be made, I believe it shouldn't have F.L.U.D.D attatched to you the whole time, but instead it should be a special power-up that has a different ability depending on the level design; kind of like what Galaxy did.

Ice Climber

Although Ice Climber hasn't aged well, I still think it deserves a sequel. If it did get a sequel, I'm not sure how exactly it would go over, but it seems like it could be pretty good if done right.

Ristar

Another game I haven't played, though I plan on it, but it looks like it has a unique idea, and its unique idea could possibly work well in 3D. I don't think this game will ever get a sequel though, but it would still be cool to see.

Shadow the Hedgehog/Sonic the Hedgehog (2006)

These games were great, and they need a sequel. They're VERY underrated!

You didn't actually think I was serious about Shadow the Hedgehog and Sonic 06 did you?

As for the rest of the games, they deserve a sequel in my opinion.