My #1 box at this point is a long box from Russell Beard (Beard Hunter Turkey Calls), I'd like to pick up a short box from Mr. Bob Harwell before spring as well if I have the extra money.
I've seen a lot of calls that look great that don't have a turkey sound anywhere in them, and that's one thing I would certainly look out for when buying a box call. This is why I prefer to run any box I can before I buy, because even two made of the same materials won't always sound the same.