My new friend, I think I have just the series for you. The books may not be the longest, but the series is currently 15 books long. It's about a wizard private detective living in modern day chicago. Hes got a mouth like spider-man, and basically spends the series slapping things that are evil and way bigger than him in the face. The first one is call Storm Front.
He deals with demons, werewolves, vampires, fairie (not the tinkerbell kind, but the kind that would rip your head off to bathe in your blood). It's a great read for those of us into that kind of thing. You know, the kind that finally paints vampires as the obvious bad guys they are supposed to be... but that's personal opinion.
Dresden also seems to find a way (his fault or not) to burn down a building XD
The books are by Jim Butcher, who also penned the 6 book Codex Alera series.. Basically, he was a member of the Delray Online Writer?s Workshop and he was challenged in the middle of a heated conversation about writing. The challenger bet that Jim Butcher could not write a good and enticing story based on a lame idea. Jim replied that off course he could. Actually, he would write a cool story based on two lame ideas of the challenger´s choosing. The lame ideas chosen were the Lost Roman Legion and Pokemon.
There's also the Forgotten Realms books about Drizzt Do'Urden the Dark Elf. 20+ long, and you can get fat books that contain about 3-4 books.
I also highly recommend the Disc World series. While the books may be short, they're hilarious fantasy novels.
The Tao of Pratchett (the author): Build a man a fire and he's warm for a day, but set a man on fire and he's warm for the rest of his life.