Oh damn. I was hoping you had some cool suggestions... OK, well Don C is the best ever, IMO. Don Caballero 2 & Singles Breaking Up are their best albums. Rumah Sakit's self-titled album is great. They also did one called Obscured By Clowns (love the PF references). Piglet's album Lava Land is math rock your girlfriend might even like - more 'pleasant' and accessible than most. I heard some insane stuff from Girraffes? Giraffes! on lastfm.com.
I've always been mostly about the talent, which is what I love about Mr. Bungle, and that's what caught my attention when you mentioned them in the thread.