I've been riding motorcycles for over 30 years, and I just don't see them as BOVs. There's really nothing that will go road/dirt. If you get something big enough like an FLH Harley to carry any amount of gear, it won't go off road. If you get a trail bike, you won't be able to carry virtually anything, as it will throw your balance all off. In a situation where it's all highway to get out of Dodge, I'll pack my RoadKing and lane split from here to kingdom come. If the roads are out, I'm SOL with it though.

That said, a good 4WD ATV is probably what you're looking for. I've been asking around to the guys who have them for fun vehicles. They're solid, will go just about anywhere, more so than a dirt bike in most cases, you can add a winch, travel packs, rifle scabbard and a passenger if need be. From what I've gathered, you're looking at about $8K minimum if you go new.