I have a Mossberg 500 with a rifled barrel. It came with a crappy scope, and I want to upgrade. What would you guys suggest in the $200 range?

Nikon Pro-Staff 2-7x 32mm. Compact,with good optics. All you need for a slug gun. Cost $129.00

I personally don't like magnification on my slug guns. It's rare to get a shot over 100yds here in central Iowa anyway. I have Bushnell Holosights on my Benelli Nova and my son's 870 20ga. I have one of the multi reticle Bushnell red dots on my 870 12 ga. I got the holosights on e-bay for under $150 ea, but they run about $250 at the store. They are hard to beat for rapid target acquisition. Where the dot is, the slug goes. The Nova had been my slug gun, but I got the 870 12ga with cantilever barrel on a fluke low bid on Gunbroker, so I put a Boyds thumbhole stock on it and the multi-reticle red/green Bushnell sight (e-bay, $45), and it has become my new favorite slug gun.