Thje coolest Planets I've ever experienced in Sci-fi are the four worlds from the "The Four Lords of the Diamond" A series of four science fiction novels by author Jack L. Chalker.

"The Warden Diamond is a system of four planets, each very different from the other, ruled by their own lords, collectively called “The Four Lords of the Diamond.” Each planet of the Diamond has its own special “Warden Organism,” a symbiotic microorganism that lives within the inhabitants of the planets. However, the organisms destroy their host when he or she leaves the Warden Diamond, making the planet system the ideal prison colony for the Confederacy, a massive space empire."

The series features four books, each centering on one of the four planets of:
"Lilith: A Snake in the Grass" (Del Rey 1981, ISBN 0-345-29369-X)
"Cerberus: A Wolf in the Fold" (Del Rey 1981, ISBN 0-345-31122-1)
"Charon: A Dragon at the Gate" (Del Rey 1982, ISBN 0-345-29370-3)
"Medusa: A Tiger by the Tail" (Del Rey 1983, ISBN 0-345-29372-X)


These books have repeatedly been in and out of press. I've bought them several times, then lent them out. Some of the most complex and thought out worlds I've experienced in sci-fi reading. Unfortunately, no movies were ever make. However unlikely, I am forever hopeful. ;:)

http://en.wikipedia.org/wiki/Four_Lords_of_the_Diamond

@Sagemind
you a chalker fan as well?
we must be related my friend.

Surely Hoth would be the coolest right? ;-P

>> ^halfAcat:

Surely Hoth would be the coolest right? ;-P


right

Risa is pretty cool, from what I've heard.