My favourite gig from hell?
Book yourself on a cruise ship playing the lounge, and embarkation, debarkation, prelude to Bingo, prelude to a fashion show, Captain's cocktail parties, etc. (7 - 8 hours a day of playing) or, a lounge in Vegas or Atlantic City - graveyard shift.
Down side: Nobody's listening and, nobody gives a damn about what you're doing.
Up side: From so many hours of playing your chops will be absolutely amazing and it will seem as if your hands and playing are on FIRE!!!! (And remember to have at least 2 good fake books with you.)