How do I full-screen QuickTime Player on an external monitor in Lion?
Solution 1:
Install QT 7 from http://support.apple.com/kb/dl923 and open your movie with QT7. Then open Preferences and select Fullscreen tab and click on your second display.
Update:
Movist is a great player. You can get it from here: http://code.google.com/p/movist/