Features required:
Container format support: AVI, MPG, MP4.
Video codec support: MPEG-1, MPEG-2, MPEG-4, DivX, XviD.
Audio codec support: MPEG-1 layer III, MPEG-2, MPEG-4 AAC.
Component video output.
Features desired:
Hard disk or SD cards for storage.
Network connection.
H.264 codec support.
Some options I know about:
Apple TV. Pluses: Cheapish, nice UI. Minuses: Requires unsupported hacks.
Mvix MV-4000U. Pluses: Dirt cheap. Minuses: No H.264.
DViCO TVIX [...]