How big do you want? is the first question to answer.
How off-road worthy do you want is the next.
I've ridden:
KTM 1090r, 690r, 990 Adventure, 950 Super Enduro, 1290 Super Adventure. 790 and 890 adventure R's
Ducati Scrambler and currently a Desert Sled.
Honda 650xr, XR650L, vfr1200x, and...