Well, I'm not really sure. I generally choose based on models and how I think I'd play them.
I like the looks of Jack Daw, minion Hamelin, Hanged, Crooked and mindless Zombies, but none of the Masters for them do much for me... but I would consider Nicodem.
Beyond them I like the Oliver Twistness of Hamelin, and the Mr. Sandman theme of the Dreamer, but I'm told they make people cry, not into playing stuff that takes the fun out of the game for somebody else. But, with that said I hear an almost equal amount of complaining about Pandora and Collette and Gremlins being a little bent. And I'm pretty sure I have a bent idea myself for a Neverborn list. So, if the entire game lends to bendy tactics, they really aren't bendy.
A voo-doo crew might be cool with some gremlins to give it that real Bayou flavor, or with dolls.
My favorite Master/Henchman will definitely be Molly. I'm a huge fan of Molly Malone lore, love the song, the Irish-ness and Molly Malone's is the name of my favorite local Irish Pub. That three model choice list kind of limits her, and Belles are not my favorite models, but I still might play her when she comes out using models from the Showgirls box.