I usually listen to upbeat techno when I'm stoned. It sounds like I'm actually at a venue and it fills me with energy. Although I listened to Number One by NDubz and it sounded like they were singing reaaaally slow.
Listen to music you like. Depends on the drug, and the trip you want to have, and what you're in the mood for. I've listened to everything from Pink Floyd to Techno and Psytrance. Downtempo can be really nice.There's some Indie bands i really like, and classical is ALWAYS good.
Psytrance, Dark Psy (much heavier shit), Progressive Psytrance, Progressive House, Minimal House, Minimal Techno, Electro, Drum and Bass and DubStep.
They all are very nice and enjoyable while high/tripping.