One of these wonderful, vanished gems is Out on Blue Six, a 1989 Bantam Spectra paperback that I've read my way through five copies of. Picture a 16-car pileup in Dr Suess country, where the colliding zithermobiles are piloted by Gibson's console cowboys and parodical caricatures out of Mad Magazine, have PK Dick and Orwell do alternating rewrites on the text, and you'll be getting close to the kind of novel that this is.
I've just re-read it. It is a wonder. We often apply the term "wildly inventive" to authors and their product, but it takes a book like Out on Blue Six to demonstrate what "wild" and "imaginative" really mean.
Out on Blue Six is set in the Benevolent Society, where all suffering has been eliminated by the Orwellian Ministry of Pain, which rearranges your genome to fit you into one sub-species or another depending on the activities it calculates you will be most likely to enjoy. All citizens of the Benevolent Society -- a culture shrouded in mysticism and poetry -- wear "famulouses," artificially intelligent consciousnesses and PDAs that advise them on behalf of the Ministry of Pain and rat them out to the PainCops in the event of serious PainCrime.
Courteney Hall is the last incisive satirist in the Benevolent Society, and her recasting of the perennial favorite Wee Wendy Waif strips as vicious swipes at the Benevolent Society sets her on the run from the PainCops and the wrath of the society at large.
Like I say, this book is out of print. Long, long out of print. But thanks to the wonderful Bookfinder service, it's possible to lay hands on 100+ copies of the novel, for prices starting at $0.75 plus shipping. I just got another copy, and I'm savoring every page.
Link Update: Looks like Bookfinder won't let you bookmark a search for more than an hour. Bugger. Here're the used copies available through Amazon. (thanks, Dan!)