I recently discovered, more than 40 years after their first record, the German band, Can. I'd heard about them forever but never bothered looking into them, until I heard a song on a local college station a few months back, liked it, and bought a best-of compilation. The song I heard and liked wasn't on the compilation, of course.

Conclusion: their influence is gigantic. They anticipated goth, punk, industrial, noise rock, electronica, everything. 90's alternative bands like The Flaming Lips, Guided By Voices, Sonic Youth, Yo La Tengo, Bauhaus, Joy Division, etc. all sound like stuff Can was doing 15 years earlier. Even today, their influence is direct: the band Spoon was named after one of their songs. Radiohead owes much to Can.

That said, I prefer what those other bands did with Can's ideas than what Can did itself. Can (especially early on) has a very cold, hard feel and a lot of it can be a bit difficult to get into - by comparison, the bands who ran with Can's ideas all feel much more organic and playful. Nonetheless, it is a pretty amazing legacy.