I would have to say Roky and the 13th Floor are both my most listened to albums. The 13th floor is a little more "instructional" while Roky is freaking orbiting the planted at 25,000miles an hour.
BTW Skeemer, the 13th floor technically was the first band that named their music "Psychedelic" If I recall they never actually played music without ingestion LSD... it was their inspiration and their demise as they couldn't keep it all together.
More of my favorites. Also unheard and under appreciated for their influence:
Silver apples, were really some of the first to be entirely electronic.
http://www.youtube.com/watch?v=aYRE-kXPoXg
The United States of America had an absolutely KILLER album, it flows from one song to the other (The album is on demonoid btw,) Sadly this was the one and only album they crafted. I would have LOVED to seen some work that had been developed a little more.
http://www.youtube.com/watch?v=C0cuX0WSdhg
Hawkwind, english space rock!
http://www.youtube.com/watch?v=POSxIOilobs"We're selling more than a cracker here," Krijak said. "We're selling the salty, unctuous illusion of happiness."