I've always been a fan of a big two-handed axe, but life as a tank often dictates that I give up a hand to hold a shield. In those cases, I make do with a (slightly) smaller axe
I LOVE the idea of picking one weapon proficiency... provided that there is equal assortment/availability of weapons of each type. I would hate to have a system which claims to provide diversity by making us choose one path, and then have the mechanics of the game dictate one single path as the "best" choice due to having better or more easily obtainable weapons.