I quietly removed Monsternomicon II from the "What I'm Reading" list. Not that I'm not reading it (slowly), just that I don't think it should really count, as I have read it before.
The two Monsternomicon books are almost unique in terms of monster books compatible with D&D. They're fascinating to read. Every single entry screams with flavor. Every entry is enjoyable ( enjoyable! really!) to read. There are very few gamebooks that I read more than once, and very few that are actually really fun (as opposed to utilitarian) but the Monsternomicon books certainly fit that bill.