Homing droid would be the best one, IMO, since it's the most able to be broken down into a smaller vehicle and packaged "smaller".
As much as I'd want an AT-TE since I love the design, I really want one to-scale. A throw-back to the old days when vehicles were big, like in the days of G.I. Joe ARAH. I'm just not expecting that though.
It's not huge, surprisingly, but part of me thinks it's just too big for Hasbro to do properly.
When rumors persist of a 1:18 scale bomber from other toy companies though, I'm always left wondering where the big vehicles are in Hasbro.
However, their track record is bad... Can't blame them. For what it was, the Gunship was a great toy overall, but just didn't move at retail really.