I like pretty much anything.... except rap
My favourtite genre is probably rock - stuff like Creed, Staind, Nickelback, Papa Roach and Linkin Park. Not a big fan of Slipknot or Korn though.
However, dance / techno music is usually better for MD because it tends to have a stronger beat, which makes it seem more "in time" to the music. One of the best "test" songs for new presets that I like is Safri Duo's Played A-Live
for reaction to music, and as has been mentioned before I think, Christina Aguilera's Genie In A Bottle
is good for testing bass and treble.
Anyhow, hoping to post some more presets later this week, just as a pre-Christmas present for you all