Are you getting tired of Vince Vaughn playing the exact same character?
I'll admit, he plays it well, and its not like all other Hollywood stars have exceptional range, but Vince seems to have the easiest job in the world.
I don't think he has to actually do anything other than show up and memorize some new lines (a lot of the scenes are probably improvised anyway) - its the exact same speech, delivery, facial expressions and mannerisms.