This one's a given really but I shouldn't assume that you know it. If you don't then welcome to some of the most innovative electronically produced music released in 2001. It still holds up today and I think it probably always will. I first heard this at an Aphex Twin gig in Cambridge, England in 1996 (!). There were two people dancing around on-stage dressed fully in teddy bear outfits with masks of Mr Twin's faces on them. One bear was bright pink and the other was bright green.

I think that was the best sound quality I've ever heard at a gig.