Whites lineman boots. they are spendy but after having to wear my redwings again while they were rebuilding my whites i don't care what they charge im never going back!
Right now im on Wesco Jobmasters (heavy but awesome boots, got mine on eBay new for $190 with original box and receipt), and I just got a pair of Timberland Endurance Pro's for ground and footlocking - They are nice leather and lightweight, but I dont see me getting more than a year out of them.
I highly recommend Merrills, I wear them for normal footwear. But as has been said, they probably arent the most durable longevity wise for work.