Me, when I'm rp'ing it varies upon the mood I'm trying to establish or what I'm feeling. It can range from love songs to when I'm in soft moments with my wife to hard rock and metal songs when I'm raging or pissed.
One common song I do play when I'm using any of my lickers is Slipknot's My plague (New Abuse Mix). I also do Rob Zombie, Disturbed, Rammstein, Metalica, Pink Floyd, Janice Joplin, Jimmie Hendrix, Linkin Park, ACDC, VNV Nation, Lacuna Coil, Collide, Nightwish, Breaking Benjamin, Trust Co., GodSmack, Annie Lennox, POD, Korn, Mudvayne, Steppenwolfe, Soil, Orgy, ZZ Top, Static X, a little Marilyn Manson, Fuel, and many more. I love all sorts of music and soundtracks to listen to, it just depends on my overall mood, the rp (if I'm rp'ing), and the moment which is happening.