Love J-Pop? How about J-Hiphop? If you do, then Dragon Ash would be the trailblazer of this genre. Featuring fresh, hip-hop tunes (complete with glorious, shameless Engrish), they have branched out to not only hip-hop, but also light pop, techno and Spanish.
While they have rarely contributed to the anime subculture, they have contributed a lot to J-Culture.