I am sure you can get delivery from any of the big chains. There is also a Giordano's near by that would likely deliver. Truely the best pizza outside of Chicago.
As to delivering right to the room, that depends on the hotel. Some won't let deliveries be brought up even if you gave your room number. Some require they call up and that the guest come down to the lobby to get it.
I have never had Giordano's thin crust traditional pizza, which is likely more like your traditional pizza you are used to. If you go for the stuffed pizza (which we always do) be prepared, it is not your standard pizza. Some people don't like stuffed deep dish pizza's. If you are one of them, go for the thin crust. We truely love the stuffed pizza's, the only ones better are in Chicago.
Haven't had enough to comment on best.
As for delivery to the room, our experience at least when staying at Disney on-site is that they call you and you meet them by the lobby entrance.