I go with the multi head screw driver as Robertson and Torx and hex keys come in handy as do various sizes. It it is most efficient solution to cover a wide range of application. I also like a few jewellers screw drivers - Phillips and common, does not take up space and come in handy (fixing glasses etc).

As for other stuff:

-painters tape
-mini Level
-some screws and drywall plugs
-Crescent Wrench
-mini flashlight

....and never forget these - safety glasses!