Check out Kyuss - Demon Cleaner. That song is made for blazing.
Stairway to Heaven is classic, always good.
Also I went into a trance state when I listened to Teardrop by Massive Attack while stoned.
If you like metal, Internal Primates Forever by Mudvayne is the sex.
Well aside from those favs, some bands you should check out are
Kyuss
Queens Of The Stone Age
Tool
10 Years
Black Label Society
Clutch
Pantera
Opeth
Deftones
Enigma
Finger Eleven
Fu Manchu
Gorillaz
Jimi Hendrix
Mudvayne
Porcupine Tree
Rage Against The Machine
Radiohead
Soilent Green
Tenacious D
System Of A Down

As for rap, im not that big on it, but I really enjoyed Ice Cube while baked.