And I'm an admittedly biased authority [grin]
Lookit this bit:
ADVENTURE/RPG: for fans of games like Fallout 3, Oblivion, and Fable, look for books that have the following characteristics: Magic/Supernatural, Journey/Quest, Quirky Characters, Fantasy/Science Fiction. Character Development.
Horns and Wrinkles (Houghton Mifflin, 2006) by Joseph Helgerson
Mortal Engines (HarperTeen, 2003) by Philip Reeve
Percy Jackson series by Rick Riordan
The Septimus Heap series by Annie Sage
The following books have gaming plots or contain a gaming element and are perfect for recommending to gamers:
Brainboy and the Deathmaster (HarperCollins, 2003) by Tor Seidler
Cathy’s Book (2006) and Cathy’s Key (2008, both Running Press Kids) by Sean Stewart and Jordan Wiseman
Discordia: The Eleventh Dimension (Hyperion, 2009) by Dena K. Salmon
Epic (2007) and Saga (2008, both Viking) by Conor Kostick
Heir Apparent (Harcourt, 2002) by Vivian Vande Velde
The Worldweavers series by Alma Alexander
...so. Now you know....