Rockplayer's a solid video playback utility that handles most file types smoothly. If you're struggling to play back a file, chances are that RockPlayer will allow you to watch it.
The paid version of Rockplayer isn't available through the Android market, although you can buy directly from the software vendor, or make do with the free ad-supported version.
It'll play back most of the common video formats, and didn't even baulk when I asked it to play back Santa Claus Conquers The Martians as per the screenshot above. It's probably worth giving it better fare to work with, however. [RockPlayer]