I've always enjoyed how Ultron-6 basically had a rocket for a lower body and he seemed to pilot himself with built-in control sticks.
My attempt was made using parts from War Machine ,Iron Man,and a Fantasticar plus various fodder. The head is a cast from a mold I made of an Ultron head from ML series 8 Iron Man's display stand.
Ultron-6 fits securely onto a Toybiz ML type display stand so it can be posed in flight.
It can also fire an attack disk if you slam down on the cylinder found in the back.