A couple years back, I decided I needed tools for the back of the truck. This truck sits outside overnight at my real job, so theft is a real possibility.
I have a rollaway tool box full of mostly Craftsman stuff in my garage, some of which I've had for close to 30 years. I didn't want to risk any of my "good" stuff carrying it around in the truck.
Using coupons, etc. I was able to accumulate what I consider a fairly comprehensive set of tools for the truck for around $120. This includes 1/4", 3/8", and 1/2" drive sockets, pliers, screwdrivers, pliers, and wrenches. Only thing I'm light on is metric stuff.
So far, the stuff has done everything I've asked of it. I don't turn wrenches for a living, but I have been known to get into some pretty heavy duty shade tree stuff.
I do occasionally pick up some other things at HF to help round out the set, and even complement the set at home. I'm strongly considering getting a set of ratcheting box end wrenches; last time I was in HF, they had them on sale for $19 for the 7 piece set. I looked at the local hardware store, and the same Craftsman set was over $60. I didn't look, but wouldn't want to bet the Craftsman set was domestically made.
I keep a close eye on prices if I am interested in buying; it's not uncommon for there to be several coupons circulating for the same item at different prices. My rule for shopping at HF is I never pay full price and always get something for free. As someone else said, I also shy away from their electrical stuff; to me it just doesn't feel right.
In closing, I think selectively chosen HF stuff is fine for the hobbyist/weekender like me. If I was bending wrenches for a living, however, I think it would be a different story.