The current project I am working on has some monsterous sprocs. Theres one with aroudn 750 lines I never want to touch again.
A fair amount of business logic was in them before I even began, and as time has gone on that has only got worse. They are a pain to debug and a bigger pain to alter. I would love to refactor all the logic out of them but pressure to add new functionality means there simply is not the time. Classic example of why it should be done right from the start.