Ive got a great video of him falling over drunk a few years back.
Bush that is.
I vote for urban rubble too, Im doing all my dark angels in it.
And the forge world extra base kits also fit in nicely, Ive got all the space marine ones, and they do work nicely.
Mind, not a lot of metal figures will sit on them, its gotta be plastic ones, and you have to do a little carving/moving limbs to make them really fit.
But Ive taken to grinding old sprues up with a meat grinder to get larger bits, and you get this funny kind of shaving dust at the bottom, and Ive mixed that freely with sand for more effect, so two pots, one of big bits to be painted up as brick and steel etc, and sand/dust mix for general crap.