Sufjan Stevens and Sly and the Family Stone.

Pulp (Common People came out during my non music years. Great song.)

Nick Drake (I knew about him, but comments on this site inspired me to get the albums, which I love).

I'm sure there are more, but they don't spring to mind. I wish this website (and the world wide web itself) had existed when I was 19 or 20, as it would have been a lot easier to find the good stuff here than the way I went about it.

Gnarls Barkley, Echo & The Bunnymen, The Cure, New Order, Dusty Springfield, Moby Grape, Eric B & Rakim, probably a few dozen others.

I don't know what you really mean by "easily encountered", but the artists I would probably have never listened without AM that I now love are:

The Velvet Underground
Nirvana
Radiohead
Stevie Wonder
Talking Heads
The Smiths
Miles Davis

And that's just in the top 40

I just realized that I never answered this question myself!

Just off the top of my head:

Lou Reed/Velvet Underground/Nico
Franz Ferdinand
Can
Echo and the Bunnymen
Patti Smith
Tubeway Army/Gary Numan
Sparks

moonbeam, yes you have. second post lol.

Oh shit!