I don't use this for workouts but I do use it for work, when I'm all pumped up and want to stay "in the zone" coding for as long as I can... I bet it would work well for the gym too though; I should try it out.
AudioBody - You Gotta Tap
Battles - Atlas
Booka Shade - Body Language / Interpretation
Chicane - Poppiholla
Daft Punk - everything
Darude - Rush (album)
Digitalism - The Pulse
DJ Tiësto - In Search of Sunrise 3 (album)
Fever Ray - If I Had a Heart
Jon Hopkins - Insides (album)
Junior Jack - Trust It (album)
Little Boots - Stuck on Repeat
Mux Mool - Night Court
Rammstein - Liebe Ist Für Alle Da (album), Mutter (album), and Du Hast
Ratatat - Falcon Jab
Works better than caffeine.