All the good San Diego bands, are just that, already pretty famous... Drive Like Jehu and everything else related, obviously... then The Album Leaf, Pinback, Black Heart Procession, Grand Ole Party, Three Mile Pilot (kinda underground?), The Locust, Sleeping People, The Plot to Blow Up the Eiffel Tower, etc. etc.
But here's one still-great undiscovered band... they have 100K myspace plays, so that's still
relatively small... I guess one might call this "post-rock," just because they're mostly instrumental, kinda mathy, and all kinds of epic...
http://www.myspace.com/japandi
They call themselves Japandi. For fans of Don Caballero, Tera Melos, Mogwai, and other instrumental titans.
FUCK YOU AND YOUR FUCKING CITY
But I'd still take Ethan over Chasny, even if Six Organs>Howlin Rain... and Santa Cruz>Seattle, just by a hair.