The ever-amusing Cat Valente has come up with a scale of science fiction famousness that starts at Trout and proceeds to Legend. For example, quoting from her post:
"Keeping in mind that two Scalzis make a half Gaiman, and at least two Gaimans are required to enter the next level, the Legend scale, which included canonical authors like Ursula LeGuin, Jane Yolen, and Ray Bradbury, this should allow us to pretty well pinpoint most authors."
It's really worth reading the entire thing. Click on the link, and then tell me what you think!