It's usually certain aspects of games that get up my nose, rather than individual games being complete pants, though a few do spring to mind:
A lot of the budget games, particularly released on the Simple 2000 series and released by 505 games are beyond the pale. They aren't even finished products half the time, absolutely abysmal.
Freakout/Stretch Panic suffered from the same problem - celebrated dev. Treasure decided to treat gamers to little more than a tech demo with some bosses. Treasure love their bosses, and the bosses love them right back, that's fine. What isn't fine is the floaty control of the character, the completely wasted stretch mechanic (there's precious little to actually do with it) and the best bit of all - outside of the bosses themselves, there is only one, uno, ein, singular non-plural enemy type in the platform style levels. One!
The way the game works is that points are needed to unlock the bosses from the central hub and to perform the attack that lets you properly defeat them. These points can only be obtained from the 'platform' style stages by defeating the single enemy type. Hence in order to get through the bosses (the one element of the game the developer could be bothered to finish) the player has to repeatedly go through these stages getting the better of this enemy. The game would have been pretty decent if they'd actually sat down and made some proper platforming levels and adjusted the controls.
Some games get halted part of the way and reworked into something else (like Silent Hill 4), it seems instead they just pushed this one out for release. Bizarre.
Sonic for the 360 is another gobbler. I hold my hand up, I thought you guys were being whingers when you said it was c-c-c-c-crud, but having played it I think even less than ye do :S Obnoxious is the word I'd sum the game up as. The camera is all over the place, to the point of irritation, the floaty controls drive me up the wall and I can quite happily say that this turd will never grace my 360 again. I cannot believe that 2D platformers for non-portables have been made extinct in exchange for floaty-controlling garbage like this.