I just tried out a Crescent wrench that I picked up on my last trip to Costco. Til now I hated adjustable wrenches, but these are great! They'rer called "RapidSlide." Instead of the knurled worm adjuster that we have all come to know and hate, these adjust by movement of a tab that slides up or down the handle. Somehow this is geared to the adjustable jaw, and it allows you to close the jaws on a nut while holding the wrench in one hand. On top of that, once the jaw is closed on the nut, it doesn't wiggle or slip open even slightly.
I broke mine in on a plumbing job, where I used it to tighten things like unions and bushings. Since they are cast, the flats where the wrench fits are not precise. With this wrench you can open the jaws, slip it on the fitting, and close the jaws, all with one hand.
Usual disclaimer: I have no interest in Crescent or Costco--I just want others to know about this new toy.