My list of most useful tools would be :-
Cordless Drill with two batteries - always good to go. I have a heavy duty contractor grade one that does all the grunt work. I also have a smaller DIY type drill. I use both on most jobs. One for drilling, one for driving screws. Saves changing bits.
Air stapler. I just love it
Framing Nailer (paslode). Cause I can't swing a hammer too well !!!
Various assorted clamps. Can never have too much clampage.
Cordless Drill with two batteries - always good to go. I have a heavy duty contractor grade one that does all the grunt work. I also have a smaller DIY type drill. I use both on most jobs. One for drilling, one for driving screws. Saves changing bits.
Air stapler. I just love it

Framing Nailer (paslode). Cause I can't swing a hammer too well !!!
Various assorted clamps. Can never have too much clampage.