Any fan of Science Fiction paperbacks from the 70s will recognize the work by Gene Szafran (11 April 1941 - 8 January 2011). His work graced a series of paperbacks by Robert Heinlein, Robert Silverberg and dozens of others. Below are three covers from my personal bookshelf of his covers. And I'm going to admit that I bought these three books purely based on the covers. Not that I wouldn't have bought the Richard Matheson collection anyway. I think they're a nice example of some sexy psychedelia - barring the silhouette of the middle-aged cat on Vital Parts.
Again, my crappy photography doesn't do the covers justice. If you're interested in seeing a whole lot more of Gene Szafran's work, check out the link provided.