I have used several different shocks in the past... Rancho RS5000 & RS9000 series, KYB Gas-A-Just, Monroe Gas-Magnum, and Bilstein.
My top two favorites have been Bilstein and Monroe Gas-Magnum... in that order.
The Bilsteins will run you from about $80.00 - $100.00 each for the shock plus labor to install if you opt to have it done by someone else, where as the Monroes will cost from $43.00 - $60.00 each. I myself consider shocks, brakes and tires to be at the top of the list when it comes to going with the best product available and would consider using either of the two shocks in the future... Bilsteins or Monroes... I am running Monroes on an F250 Super Duty 2WD and Bilsteins on a Ram 2500 4WD right now.
Also... I have found that a fellar should consider 100K miles of service from a shock to be pretty much about all your gonna get out of one... maybe less depending on the road conditions driven on most often.