Wolverine's with DuraShock are the way to go if your walking on a cement floor all day. I used to wear out a pair in a year but switched to a different style and these are gonna be around for a few years. Ive had Georga Loggers, Red Wings, Carolinar, and Lacross and they never lasted more then a year.
Had Cat Alaskas, but they don't hold up well in wet conditions. Tend to shrink and harden. Have had Wolverine since (yes, I know Wolverine makes Cat's boots), but they seem to hold up better. Also changed jobs, so not as much wet conditions now. Last year I bought a pair of Wolverine Durashocks...man, they are comfortable, durable, and not too bad on price (compared to other big name brands) JMO.