I've been buying all my hiking footwear at REI in Berkeley. I haven't found it useful to rely on the staff too much, as they all all seem to have their own ideas of what boot would be best for me. I've tried on a number of name-brand boots, some of which I hated from the first step even though they were very popular with other wearers. They just didn't seem well suited to the way I walked, and I was in no hurry to learn a different walking style.
What I settled on years ago was Merrell Moab Ventilators, the "mid" version. I've tried the "lows" too, and wear them around town, but for serious hiking I prefer the mids. I sometimes wear Moab Waterproofs when I'm expecting rain, but I find there's an increased risk of ending up with unexpected blisters. I'm guessing that the moister environment inside the waterproofs makes my skin less resistant to friction, especially in warm weather.
It took me several tries to get the sizes right (different sizes for different uses, it turns out). Early on, in my pre-Merrell days, I noticed that when I'd done a lot of hiking my shoes would start to feel tight. I solved that by first switching to Merrells in a wide size, then finding arch supports that worked for me. I typically throw away the standard Merrell innersole and replace it with a Dr. Scholl's "custom fit" arch support sandwiched between two Spenco flat insoles. I seem to have found the right size of Merrells to accommodate that particular combination, and it's been working really well for me.
I used to bruise my toenails a lot going downhill, until I went to the "mid" height for the extra support
and made sure to tighten the laces before starting down. At one point I started getting a blister on the side of my heel, of all places. It seemed to be from the friction as my heel squished up and down on all the padding. I added Spenco heel cups and that seemed to take care of it. For some reason the heel cups didn't want to stay in place till I stitched them to the insole directly under them.
A few years ago I bought a pair of "winter" boots to experiment with -- Moab Waterproofs a size or two bigger than I usually wear, so that I could fit two pairs of "expedition" socks inside. They weren't what the staff recommended and I had no idea how they'd actually work out. I recently got my first chance to try them out in Yosemite Valley, and they worked perfectly for me. My feet, at least, had no idea I was walking in snow at temps in the 20s.