Gotta say OpenATV as a base, I personally have a script to run upon boot that
Cleans out the existing chans (for most OpenATV images come with 19.2 chans on)
Installs ABM, CrossEPG, EPGimport, DreamPlex
Installs the skins I like & picons
Installs the Softcam menu, then downloads the Cam I use...