Recently, Stephen Michael Sechi was asked how Jack Vance's novel The Dying Earth served as an inspiration for Talislanta. He responded:

• Vance's imagery, which is by turns evocative, beautiful, and disturbing...
• The strangely mannered way in which his characters speak, which I like a lot better than the "Thee and Thou" school of fantasy writing, or its opposite, the silly/anachronistic style of writing characteristic of TV fantasy writing, ala "Hercules". In Vance's books it seems that everybody is a wiseguy - even the so-called "monsters" have a decidedly dry sense of humor...
• Vance's idea of how magic works in his world (which, BTW, formed the basis of the first RPG magic system, D&D). From the names of his magicians to the names of their spells, it's very colorful stuff...
• His unusual and eccentric characters, cultures, and creatures.

I think it's fair to say that Vance is an acquired taste - though he's well-respected by other fantasy and sci-fi writers, he never was hugely popular with the reading public. After I read Eyes of the Overworld I was hooked. Of his many books I think my favorites would be Rhialto the Marvelous, the "Lyonesse" trilogy (more of a traditional fantasy, though still plenty quirky in spots), and his sci-fi books, the "Planet of Adventure" (yow, what a name - publisher's choice, not Vance's, BTW) series and the very strange Palace of Love (gotta like that Mad Poet character) from the "Demon Princes" series.