I bought TkcVideo for my 760 and it was crippleware. Couldn\'t do fullscreen at all, had these crappy borders. When asked tkc said fullscreen was impossible due to something or other which was bullshit. Dr.Z and mplayer-w100 (the one with the ati w100 chip driver) as well as the packed in Sharp MPEG4 player all do fullscreen no problem and I\'ve toyed with them a lot.
It\'s been a few months, but I\'d look carefully before forking out change for tkcVideo for one of the VGA units (considering those crooks even refused to admit having a fake, crippled fullscreen mode was a problem).
Of the other players I mentioned I prefer mplayer with MPEG2 (which lets you pump the bitrate up since it\'s easier to decode). The Sharp player does really nice as well, although it requires encoding in MS ISO MPEG4. The colors are really vivid, but I haven\'t figured out if that\'s due to overlayed playback or something the Windows Media Encoder does beforehand.
Dr.Z performed well, handily beating mplayer at some more normal MPEG4 trials before I got my settings down for mplayer. Dr.Z can\'t play MPEG2, though, so once I figured out that was superior for such underpowered devices I didn\'t finish comparing those two.