I found 1/2 inch drive units did not have the power I needed at times, so I jumped up to 3/4 inch. The 3/4 inch will spin off bearing seal nuts and
that pesky nut that holds
the u-joint on the differential.
The only 3/4 I found under $100 was at Harbor Freight. I had my reservations
when i bought it last summer, but it works great! I can hook it up to the Glad Hand
on either my M109A3 or my M52A2 and the air brake system with power it enough to spin off the lug nuts with ease.
Ah, the yoke nut... I know that one well. Unfortunately I've never had the pleasure of removing one in the garage, it usually takes place out on the road somewhere. I've found the easiest way is a 1/2" breaker bar with a 6 foot fence post on it braced against the ground, then you hook up tow chains and drag the vehicle forward untill the nut breaks loose.
If you're just looking for a basic set that will get you through most jobs and not heavy use then the cheap stuff isn't bad.
I recently picked up a set and a compressor at Sears. They were having a sale and I walked out with a one and a half horse 20 gallon compressor, 300ibs 1/2inch impact, 3/8 ratchet drive, and air chisel set along with a couple lines and all the fittings, air gauge etc. All for about 320 bucks.
Sure, it would be nice to have a quality 600lbs impact that can rip through the toughest jobs, or a nice pricey chisel that cuts through steel like butter, but for under 100 bucks I got a set that will do for now.
Now if you're looking for a tool that will see daily use, and/or serious tough jobs then you're looking for more of an investment.