I think the dollar store ha ha.
My girlfriend is in love with the dollar store. I never really cared for it, until I noticed that I can buy super cheap garden lights with mini solar panels. Now I'm just thinking what to do with those solar panels... and what else I can get there!
Otherwise, isn't duct tape MacGyver's favorite tool? Well, I guess that's a material. Then his Swiss Army knife, right? I don't know about my favorite tool. I use dikes more than I should, but I also seem to use an X-Acto knife everyday for one reason or another.
Those are all good things. I find razor blades to be extremely handy as well.
And I know how that goes. My wife is addicted to the dollar store ha ha.