Something from the Nightside, by Simon R. Green
Brilliant, different, snarky fun. The book, like the characters in the book, doesn’t take anything too seriously, but it sure is fun. I’ve read all the Nightside books that have been released so far (11 of them), and though things might start getting rather worn by book 9 or so, the first ones are truly memorable fun. The author has created a uniquely twisted mirror-world that is hugely fun to play around in, and a good cast of reluctant, misfit heroes to follow through that world. Give it a try.