World stuff: Jorge Ben, Ozomatli, Gilberto Gil, Carlos Patato Valdez, Andy Palacio, Seu Jorge
Oz/NZ rock: Beasts of Bourbon, Hoodoo Gurus, Paul Kelly, Split Enz, Neil & Tim Finn solo with Missy Higgins, AC/DC
Americana: Nick Lowe, Wilco, Elvis Costello, The Flaming Lips, Neko Case, Guided by Voices, Woody Guthrie, White Stripes, Green Day, the Bees US, Johnny Cash
Soul & blues: Sharon Jones and the Dap Kings, Nashville's own Dynamites, Isaac Hayes, the Staples Singers, Five Blind Boys of Alabama, the TSU Tornadoes, Ann Peebles
Protopunk: Television, The Stooges, the Minutemen, Mike Watt, Black Flag, the Damned, the Buzzcocks, and what Wombat said about Stiff Little Fingers
Dance stuff: Goldfrapp, Benny Benassi, Q Burns Abstract Message, Venus Hum, bt, DJ Spooky
Disco: BeeGees, Abba (who doesn't?
)
There's lots more where this came from. Long story involving marrying another huge music nerd and having a good friend who owns a record store...