Lightwave FTW!

Ive worked with Maya and 3DS (dos) and 3DSmax. But for speed and fast vizualization i can get stuff done much faster in Lightwave then either other package.

I can make detailed cad like drawings, but i ususally make simple basic shapes and get a look and feel for what would work or not on a robot.

Maya has got the best dynamics engine though, it is so much fun to play with.