Jack Black is a versatile guy that likes lots of metal, but Tenacious D is a rock band.
My Rig:
Yamaha RBX 375 bass
Peavey Millenium BXP bass (won at Summer Slaughter 2010, signed by all the bands)
Eden Nemesis NC410 320w combo amp
Check out Tyrannicide, my death/thrash metal band:
Pretty much all of the songs from the movie are awesome, but I also love Karate. Actually, pretty much everything I've heard I like.

...having said that, this shouldn't be in this forum.