With the big megaplexes, it's almost too easy.
My roommate and I can watch movies no problem, and one day we were board and successfully got in 5 movies.
Of course it usually means seeing a crap movie as filler. We didn't quite see all of Boogeyman, but we got the gist of the movie. Maybe missed the first 20 minutes.
Off the top of my head, we saw Million Dollar Baby, Hitch, Boogeyman, some other thriller, and ended with Hide & Seek.
We just did the 5 to see if we could one up the 4 we did a long time ago. The Mummy Returns, Crocodile Dundee in LA (haha, lameo thriller...though my roommate had never seen any of the dundee movies so all the old recycled jokes were new for him), and then One Night at McCool's.