This is what I use...the 30mm model
http://www.bushnell.com/general/rifl...hy_73-0135.cfm
I like it because it has 4 different reticles, and both green and red illumination. The green is very nice in low-light/early morning conditions. I usually leave it on the circle encased dot for turks, and then switch to the crosshair for deer. I've used it for 3 years and am still on the original battery. I am quite anal about always turning it off every day, and usually have it off in the woods unless I know a gobbler is around.
I have it mounted on a B-square mount atop my Ithaca 12 ga., and after I zeroed it in it has not moved.
S&R