DEFINITELY check out TMV and P-Groove. The Mars Volta is not in the same genre as any of those other bands, I don't know exactly what I'd call it. It's pure rock though. Check out De-Loused in The Comatorium and Frances the Mute by them.
Perpetual Groove is a jamband plain and simple. Check out www.archive.org
and download some of their live shows or check out their studio CD's, All This Everything and Sweet Oblivious Antidote.
I agree tDB fell off for a while but I have quite a few shows from their 06 tours that are killer. They're coming back and coming back strong.
It's great to see someone with the same musical tastes here. Now I'll stop rambling...