Think in terms of 3 or more inches of eye relief as being the best scope.
Vortex and Nikon are popular while Leupold is also right in there as better scopes. The Bushnell Banner and Trophy are scopes are right in there. I have some Simmons Pro Hunter scopes on a couple of my smokers, one a 50 cal the other a 45, and they have been super dependable with decent eye relief and both under the $100.00 mark with real nice glass.
Do some snooping at http://www.OpticsPlanet.com and check out the whole line of scopes there. Most everything found there that will work on a medium to high powered rifle will work as will just about any scope designed for a shotgun.