One plot device that I can tolerate is the classic "three version story". What usually happens is two main characters will get into a fight about something that happened in the past. One character tells a totally exaggerated story that makes the other character look bad. The other character does the same, and while their story is just as exaggerated as character 1, it's also completely different. In the end, a third character shows up and tells the audience what really happened.
I like this plot device because (a) it's not used quite as often as some of the devices already mentioned and (b) from a comedy standpoint, it always brings out the best in the characters. Plus, the exaggerated stories are usually pretty funny.