Altbergs.
I've worn mendil, lowa, issue boots, Danner, matterhorn and all kinds of supposedly indestructible boots. All have failed me except Altbergs. They were my only choice of boot in the army (most other's too). I've used them in Iraq and other rock infested, scree covered ***** holes.
I'll back up Deerman's claim that made to measure service is free. It was common practice for us to even draw around our own feet onto cardboard, post back to the Mrs and have her order from the factory in Yorkshire. Some guys visited the factory but I never bothered, however service men were always made welcome.
For those who claim them go be uncomfortable. Have you ever actually had your feet professionally fit? No offense, but there's alot more to it than just the length and width of your feet. Especially when you expect them to perform faultless under extreme conditions. A quality service will include instep shape, arch height and position, foot height, toe shapes (seriously - like some people have a longer toe than that of the big toe, etc).
Lastly, regardless what type you buy, care for the bloody things. Regularly check the stitching and eyelets, wax them and consider it a regular part of maintenance. Wax your boots when you clean your rifle (assuming you do clean it) and forget about polishes. You want the leather protected, kept supple and avoid them drying out; not glossy.