For the poll, I voted for the beautiful Madison and AltNation. I only frequent 3 rock stations on xm: the loft, xm cafe and xmu, but some others I really enjoy are holly, 40's, watercolors, escape and upop worldspace. I also liked the format of 60's but have heard too much 60's music in my life to really get into it.
xm sure has some quality radios. that XMP3 looks outstanding.