With bad knees, I need some serious shock absorbers on my feet and these Merrell's are the ticket.  They're built to last (I usually replace them every two years, and that's only because I've worn the soles down.  I prefer the Gore-Tex model for its water resistance (snow/rain).  Some say it's too hot in the summer, but doesn't bother me....  Great shoe and equally great looks.

Highest recommendation.