Many great recommendations were made including this one from callie_chan:
6) Every movie should have a ninja. This isn't so much as a cliche that should be stopped as a cliche that should be introduced. Everything is better with ninjas. Cereal is better with ninjas. I would even have voted for Bush if he'd whipped out some shuriken(well, probably not, but I would have seriously considered it for a minute).
In fact, that whole thread is worth a read.