DEFINITELY dubstep! Also House and Techno. My first songs were Warp 1.9 (Bloody Beetroots f/ Steve Aoki) and Satisfaction (Benny Benassi). I was shocked! I could not believe that a vibrator could buzz to my music. I am still absolutely blown away and a bit in shock. The cool factor has not faded, and I have had this toy for months. I would also recommend Major Lazer Pon De Floor.
Tried one at the store today. The music I tried on my phone didn't have enough bass but the store employee put on LMFAO and it was great! She said that anything with heavy bass and pulsating beats are good and that Another One Bites The Dust by Queen is amazing (she didn't put it on, but I can imagine!)