Most here would go with 3.73's. They offer more flexibility down the road and a touch more pep.
I'm one of the few that will probably go with 3.21's because where I travel is pretty flat, I'll stay stock, I'll do very light towing, and I'll spend quite a bit of time on the highway and in the burbs....so my particular goal is to maximize higher speed mpg at the expense of flexibility.
I've gone back and forth on which axle to get for months, and even after test driving both back to back, I'm still leaning 3.21's....but would note rule out 3.73's. Take both for a test drive if you can.