Alright, so I'm late and the lists are really long already, but there's two good tools that I haven't sen yet:
Heat gun, useful not only for shrinking heat-shrink tube, but also for softening and bending lexan, PVC, etc.
Electrician's Scissors. Vital for your electrical team. They cut darn near anything from wire to cable ties to small diameter steel cable. Plus with a little practice you can strip wire with them too.