I've used a Nikon M-223 1-4x20 and a Burris Fullfield II 3-9x40. I would like to get a
Weaver 1-5x24 Tactical. Depends on what I want to do with the rifle. If I'm varmint hunting I like the added power and field of view of the Burris. For "tactical" shooting in local league matches the Nikon works well, but imprecision of the point blank reticule makes me twitch for longer range shooting (3.5 MOA dot covers part of the target).