The basic idea of the scenario would be to allow people to choose one character from different shows, novels and the like and set them against a random villain/plot twist of another show, novel or so on.
Of all the character's I'd like to see in such a scenario, I'm going to go with only eight possibles and for fun assume each of them have six advances.
I don't know when I would get the chance to run this.
Note, there are spoilers in some of the links below. Also I really doubt all eight would be used.
In addition, I could see these as just examples. The idea of Monster of the Week is to have a very interactive game thing, so what you could do instead was just have everybody pick a character they want to play from some urban fantasy genre (or even other genres because of the Exile playbook) and watch the fun as everybody plays the hero they wanted.
Monster of the Week Playbooks
Alice Gallow (The Central Series) The Hard Case
Celty Sturluson (Durarara!!!) The Monstrous (Dullahan)
Dean Winchester (Supernatural) The Wronged
Harry Dresden (The Dresden Files) The Spell-Slinger
Ichabod Crane (Sleepy Hollow, TV) The Exile
Kate Freelander (Sanctuary) The Professional (formerly The Crooked)
Kiritsugu Emiya (Fate/Zero) The Expert
Mai Taniyama (Ghost Hunt) The Spooky (formerly The Mundane)