Military: Danner, then Belleville
Security: Nortiv8 (see Amazon)
Field Service: Skechers Work (no,they aren't boots...just comfortable)

I have a pair of Keen hiking boots that have lasted well over a decade and are very comfortable.

I have some swedish brand boots that are pretty comfy... Wait, are we talking about rubber boots, Dock Martin's or just boot boots(for booting)? because I never wore the first two, so can't help there.

Get boots made for construction workers. They are on their feet and in boots all day. I got a pair of redwings a few decades ago and they were my daily walking shoes until I got a car.

Yeah, I have some really comfy walking boots (by a brand called Vegetarian Shoes, I think they're made in Italy) and a pair of everyday boots by Superga which are also really comfy. You'll usually need to break boots in - maybe wear them around the house a bit with some thick socks on whilst they get used to your feet.

My Desert Rat boots are the best boots I have ever had.

I wore steel toe boots for several years for work and while they do tend to be uncomfortable at first they eventually break in and improve. For me the most comfortable were the wider boots and especially those with a larger toe box. I no longer need a safety boot so now wear the Lems boot which I find super comfy.

Knowing how sensitive I am, I can't imagine buying footwear I didn't think was comfortable.