Here's an unusual one I stumbled onto this weekend in Washington State. Normally I stay away from odd patent, obscure tool company wrenches. But this one was too cool to pass up. This 18" 6 lb. wrench doesn't need an adjustable screw. It's got an internal gear and ratchet setup to make instantaneous adjustments just by pushing the jaw to the desired spot. A push button on the side springs the jaw back to the fully open position. There's no play in the jaws once you set it like with a regular Crescent and the cleverness of the design allows miniscule adjustments while (theoretically at least) not sacrificing strength. This one seems to work perfectly. Maybe a criticism might be that you'd expect a little bit bigger opening ( this has a 2" limit) and depth for the size.

