30 years ago when I bought tools Porter-Cable was always my first choice. Their stuff was heavy duty and USA made, although a bit pricey. But now they're part of Black and Decker and I'm sure the quality is nowhere near the same.
Lately I've been pretty happy with DeWalt tools, both corded and cordless. I have the 12v drill/driver set with Lithium Ion batteries and love the compact size while still having decent power for a 12v set. For heavier work I have the Craftsman 19.2v Li-Ion drill/driver set and it also has served me well. For even heavier work I break out my old Porter-Cable corded hammer drill, nothing stops that.
Another tool brand that I've been pleasantly surprised by is Worx. I bought their 18" electric chainsaw and it's far exceeded my expectations. I dropped and cut up 4 big walnut trees with this saw with no problem at all. I liked it so much that when we decided to buy a cordless weedeater I got the Worx 20v model, and it has also worked out quite well.
I'll have to agree with those who say you have to be careful what you buy at Harbor Freight. They do sell some real junk, but some of their stuff is a bargain when you look at the price. Something I use very infrequently, I'll chance HF, and sometimes the tool is better than I expected. When I was drilling the anchor holes for my lift I needed a big SDS hammer drill and bought one at HF for something like $70. I'd have spent almost that much to rent one, and it drilled the holes easily.