One Corpse Too Many by Ellis Peters

#2 in the Cadfael series.

Night Work by Steve Hamilton

By the author of the Alex McKnight novels.

Body of a Crime by Michael Eberhardt

Decent legal thriller.

Starship Troopers by Robert A. Heinlein

I'm not generally a science fiction fan, but I stumbled across this in a used book store and thought I would give it a chance as a recognized classic. And it is very good...