I see by your inclusion of Wallflowers, Coolio, and Jamiroquai that your definition of "underground" is as eclectic as my own.
My suggestions, in no particular order:
-White Reflection (by Two-Mix [J-pop, from the Gundam Wing: Endless Waltz
-Woke up in a Car (by Something Corporate)
-The Girl All the Bad Guys Want (Bowling for Soup)
-Information High (Cream Puff)
-Boy Crazy (Newfound Glory)