I have an '08 Xterra SE 4WD.
I recently replaced my OEM shocks with Bilstein 4600 series shocks.
I bought them from Summit Racing, the cheapest on-line price I could find and it included free shipping. I believe these are the recommended replacement shocks if you don't have a lifted SUV. I have been very pleased with my new Bilstein shocks.

I'm up to 112,000 miles recently.