You know what pisses me off? How certain incredible games will probably never get sequels due to one bit of bullshit or another. Here's a few.
Super Mario RPG
Now, don't get me wrong, the Paper Mario games are really good. I avoided playing them for a while due to being pissed off that we got Paper Mario instead of a real Super Mario RPG 2. That was a mistake which I encourage you not to make. They're good games and you'll probably like them.
That being said, it's still no Super Mario RPG 2. To be a true sequel it would have to be developed by Square|Enix or someone very similar, perhaps Mistwalker Studios. There's been absolutely no hints or indication that this is going to happen and that makes me sad.
Kameo Elements of Power
This was a launch title for the XBOX 360. The events in the game suggest a sequel but it seems very unlikely that we'll get one. Kameo is a fun game with fantastic graphics and amazing music. I don't think it got the credit it deserved, most likely largely due to the "omg it has more than 3 colors it's for children" idiots.
Microsoft bought Rare a while back and seems to be, in my opinion, wasting their talents. Using them to work on the avatar system and Kinect related bullshit. The chance of another Kameo seems remote and that pisses me off.
Banjo Kazooie Nuts & Bolts
Another really fantastic Rare title for XBOX 360. A lot of people were actually disappointed that this wasn't a platformer like the previous Banjo Kazooie games. Personally, I loved the hell out of it. It was creative, original and fun as hell. The online play, until it died due to lack of people, was some of the most fun I had on that console.
Another game that seems like it'll go without a sequel due to Microsoft wasting the talents of Rare. Bullshit.