UZ

Just for the heck of it - and because I do things like this - I went through my library yesterday looking for works of science fiction or fantasy with one-word titles beginning with each letter of the alphabet. Here's what I came up with:

Arslan (M. J. Engh), Barrayar (Bujold), Cetaganda (Bujold), Dune (Herbert), Eon (Bear), Flameweaver (Margaret Ball), Grass (Tepper), Hogfather (Pratchett), Inheritor (Cherryh), Jingo (Pratchett), Komarr (Bujold), Lavondyss (Robert Holdstock), Madouc (Vance), Norstrilia (C. Smith), Orca (Brust), Pyramids (Pratchett), Quicksilver (Stephenson), Ringworld (Niven), Sourcery (Pratchett), Tamsin (Beagle), Valis (Dick), Wyrms (Card), Xenocide (Card), Yvgenie (Cherryh).

The attentive (or badly in need of stimulation) reader will note that the letters U and Z are missing.

Would anyone care to nominate the best (or, failing that, good) works of F/SF, with one-word titles, beginning with those two letters?