I've been on this doom/prog/psychedelic/post-rock/metal kick lately, ever since I got bored and /mu/ had a sharethread.
In any case, here's some of that retro-ish psychedelic rock/metal.
Black Math Horseman (Mellow post-metal, with psychedelic and doom influences. Groovy stuff)
http://www.youtube.com/watch?v=-kSUj_b2ohk
Samsara Blues Experiment (Spacey Psych Rock)
http://www.youtube.com/watch?v=_TnNb3cBzuE
Stoned Jesus (Reminds me of a less thick Electric Wizard and a slower Sabbath)
http://www.youtube.com/watch?v=dFSf9Bmj0gA
Witchcraft (Swedish band playing psychedelic rock akin to 70s Sabbath. Their first album was recorded on vintage equipment, a la EW's Witchcult Today)
http://www.youtube.com/watch?v=hKiz-QYMwlA
Wo-Fat (Ipsychedelic stoner metal, awesome groovy stuff. Their second album is amazing)
http://www.youtube.com/watch?v=vKAN8F6-zos
The Black Angels (Psychedelic Indie rock with a ton of doom/stoner influences)
http://www.youtube.com/watch?v=VvKjpGP6P5Y
Graveyard (Retro 70s psych rock. Recommended)
http://www.youtube.com/watch?v=DKUotXdybbw
I'll post more stuff later.