Gardner Dozois' Recommended Science Fiction Novels
Recommendations from one of the best SF editors out there, as listed on http://www.sfwa.org/reading/rec_dozois.htm.
To quote Dozois from the site: "This list was devised to point younger readers toward older stuff that they might not have heard of, or long out-of-print writers whose work they might be unfamiliar with, so I’ve arbitrarially given it a cut-of date of some vague point in the early ‘80s. When I list more than one book by a particular author, the one I list first is the one I recommend most strongly, but I wouldn’t list a book here at all if I didn’t think that it was, to one degree or another at least, worth looking at. Many of these titles will be out-of-print, but if young readers know authors’ names and titles, I figure, they may be able to find much of this stuff in second-hand bookstores."