I make my stuff using sets from the Lego Mindstorms series
The sets i have are:
Robotics Invention System 1.5
Ultimate Accesory Kit
Vision Command
Ultimate Builder's Set
These 4 sets are awesome, and all up include 4 motors, 3 touch sensors, 1 light sensor, a remot control (which is broken), 1 rotation sensor, the lego camera, the very awesome pneumatics set and of course hundreds of additional pieces.
Crane #1