h264 rips don't work very well for me in WiiMC-SS, but 'DVDRemux' torrents (straight MPEG-2 conversion, can even be .VOB files renamed as .mp4) do!
divx encodes are also pretty reliable, but i notice the macroblocking more.
for h264 i have an IPTV box w/ S-Video, it does what Wii doesn't, vice versa