I've got an 18v Makita impact driver with a 1/6 hex drive, you can use an adapter to fit a socket on the end, works ok for smaller stuff and is nice and light.
Also got a 24v 1/2" Clarke impact gun which I'm a bit disappointed with tbh. The Makita can do most stuff the Clarke can, you just snap the odd adapter but they are only a few quid for a set of three.
I've also borrowed the big 240v Bosch 3/4 drive impact gun from work in the past for crank pulleys, that thing is fooking amazing, there is nothing it won't undo!