I would add a couple of other useful hitches: the taut-line and trucker's. Along with the bowline, I use these constantly for attaching adjustable-length lines to things and securing items to vehicles.
They are both a part of my repertoire also. The trucker's offers a great "quick and dirty" mechanical advantage for tying things down on your car, on your boat (my mast when I trailer it, for instance); heck I even use it to tie down my trash-can lids to keep the animals from getting into the trash (raccoons, not bears!).
