Allegiance by Beth Bernobich, the conclusion of the story from Passion Play and Queen's Hunt.
Copperhead by Tina Connolly, sequel to Ironskin.
Esrever Doom by Piers Anthony, latest in the Xanth series. Here's its synopsis, since it won't spoil what's happened in the previous books:
Kody woke up in a hospital bed, not knowing how he got there. Before his questions could be answered, he was told that he was about to undergo surgery, and that there could be some side effects.... And then he woke up again, this time in Xanth.
Kody is the only person in Xanth who has not been affected by a dreadful spell that reverses how people see each other. What was adorable is now loathsome. What was ugly is now beautiful. What was loved is now hated. Kody has clearly arrived just in time Only he has any hope of reversing the spell, turning Esrever Doom into Reverse Mood.