4. Dave
This Ivan Reitman-directed political satire is one of the more potent and stingingly funny mistaken identity movies, as a regular Joe named Dave Kovic (Kevin Kline) who works a side-job impersonating President Mitchell (also Kline) is called to play the President for real after he suffers a stroke during a kinky tryst with a White House staffer (Laura Linney). From here, Kovic perfectly impresonates the President, his down to Earth attitude winning the hearts and minds of voters, much to the chagrin of Bob Alexander (Frank Langella), who was planning to use the vulnerable Kovic as a platform to stage his own Presidential ascendancy. Here is a movie that uses its mistaken identity premise to make a political point, albeit without shoving the idea down our throats. It says that, as we all know anyway, there's always someone better to serve the country than the douche who gets elected, and we all - the "everyman" - have that potential.