I have three pairs of these, and for better or worse, I wear them every day.  I used to wear the classic Dickies for work, but kept blowing the knees out.  Though these cost about twenty dollars more, they last much longer and are well worth it.  Some of the reviews have issues with the stiffness of the material - yes, they are a bit stiff, but this adds to their durability, and after a few washings they loosen up and are quite comfortable.

I like these pants because they are relatively unique, at least here in Austin, TX.  You don't see many people wearing them.  This must be due to the fact they are hard to find in retail stores.  A lot of places carry Carhartt clothing, but only one place in town carries these (a genuine farm and ranch supply store on the outskirts of town).  Though it might sound lame, I find this uniqueness kinda cool...