General nuts and bolts I use the DeWalt DCF887, 1/4" brushless impact, from their 20V Max line:. rated at 1,825 ft/lbs max torque (152 ft/lbs) AWESOME tool. I have other tools in the line and am always on the lookout for another deal. On the short list is their DCF899, 1/2" brushless impact, from their 20V Max line: rated at 1,200 ft/lbs max reverse torque.
Milwaukee has equivalent, though rated slightly less tools. Though rated slightly less, on paper, I doubt you will ever find an application where one failed where the other comparable tool excelled.
Those are the top two brands, for bang-for-buck. Milwaukee has a longer warranty. DeWalt is starting to bring plants back to the USA, and still has a vey good warranty. The DeWalt stuff tends to go one sale more often and for lower prices than the Milwaukee stuff. Retail, the prices are similar.