Who doesn't like a good concept art? I used to spend hour browsing concept art forums. I believe concept art is the purest form of creative activities a person could master. Even though I love modern CA I often come back to earlier works. E.g. stuff from 80' of 70'. Artworks from those era seem to their own atmosphere. One of the influential artists back then was John Berkey, responsible for some of the early artwork for the original Star Wars trilogy. His creations overflow with detail. See for yourself:
Images from: http://conceptartworld.com/artists/john-berkey-1932-2008/
Discovered trough https://twitter.com/70sscifiart