This is new for me, but I've been listening to more dancy music recently. Esp for car trips, I really like mashup stuff like Girl Talk and The Kleptones. They take pop music and mix it with other existing songs (often rap) to come up with something new. Kleptones have this great album that's all Queen mashups. For working, I usually want something more chill like RJD2, who is kind of house/mellow hip-hop  (he does the theme song for Mad Men, eg). In general, I used to listen to more indie/alternative stuff like Wilco, Neko Case, Elliott Smith, The Cure, Pixies. I also listen to a little classic rock like early Stones, and some jazz/swing like Django Reinhardt.

For sessions, I think my preference would be for mellow romantic indie music, maybe something like Bright Eyes' First Day of My Life, or Yo La Tengo's Our Way to Fall? But whatever else, I really prefer that ladies make their own playlists. Nothing scares away Mr Happy faster than when an ad for a bail bondsman comes up on the radio :-P