Legion

I would tell you that urban fantasy is not my thing -- but I really liked this story. The protagonist, a sort of ad-hoc detective, has 50-some "aspects" -- hallucinatory characters, which only he can see, each of which has a fully-realized personality. He does not suffer from dissociative identity disorder (otherwise known as multiple-personality disorder). He interacts with all of these characters -- and they interact with each other. Each time he takes a new case, a new character aspect materializes -- one which has the requisite expertise(s) to help solve the case (whether that expertise includes fluency in a foreign language or specialty knowledge on a specific subject).

The pages flew by. I enjoyed this story so much. I highly recommend this series to anyone who thinks that the above story premise sounds interesting.