He won the Hugo for “the Dragon Masters”, but my favourites are probably “the Demon Princes” series, “Planet of Adventure” series and his most famous work, “the Dying Earth”series.
Heres a general write-up:
http://www.nytimes.com/2009/07/19/magazine/19Vance-t.html
Hes in his mid 90s, and has been blind for a while now. The cat can write like no one else though. I have finally pretty much read the whole catalogue. Abe books is awesome for getting cheap used books.
I cant recommend Vance enough, never read a dog from him, and Ive pretty much read them all.
Freegards
Here's a bit of trivia about it (I just looked at the article about it on Wikipedia): the magic system used in Dungeons & Dragons (and some other elements of the game) is based on the Dying Earth! Since I played D&D a lot 30 years ago, and still play other roleplaying games, it may seem strangely familiar.
Also a HUGE Robert Silverberg fan.