Up to now, I have been usin VideoLan Client (VLC) to view videos on my Mac. But I don't like VLC because keyboard control is too complicated. I really like MPlayer, because I can skip forward and backwards simply by pressing the cursor buttons. Unfortunately, MPlayer OS X always changes the screen resolution when switching to fullscreen mode, which takes several seconds during which you are without sound and video.
I downloaded the source and noticed that they linked the GUI to a hacked version of mplayer which had this behavior. I simply replaced their hacked-to-death mplayer with a self-compiled version of the original code from the project homepage, and compiled a nice OS X .app binary out of it. First tests on my own Macs and with friends indicate no side effects or additional bugs. You'll find my precompiled binary right here. Simply decompress the zip file and put in in the Application Folder. You'll probably need Mac OS X 10.3.
[robg adds: I haven't tested this recompiled version...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20040715111113996