I have a few different boots for different conditions, but most of the time I wear a Solomon Quest GTX. They are comfortable and provide great stability without being too stiff like some. One of the biggest reasons I wear Solomon is because they hold up and last. I have used Lowas in the past, they are a decent boot, but they don't seem to hold up to the abuse I gave them. I own a few pair of Danner's as well, excellent boots all around with the only drawback being the weight, they are porkers. I have a pair of Asolo's as well, but they are too much for 90% of people's needs and they are a true mountaineering boot that is simply too stiff for standard walking.
I'd recommend staying away from Merrells, the quality just isn't there, sorry if this fact offends some of you. I saw another member post about Belleville's, in no way are those what I would consider an excellent boot. The only thing they have going for them is durability and life span. Uncle sugar stuck that junk on my feet in the Army and as medic I witnessed some rather gruesome victims of those boots because of their construction. There's no way I'd spend any money at all on a pair of Belleville anything. That said, different strokes for different folks, and they may not be half bad for simply walking around in, but if you carry any type of load out on your back then I'd run from those boots.
Everyone's foot is different and we all have different comfort levels and needs in a boot. Try them all on, do some research and then purchase the best boot for you, that you can afford.