Igall,
I guess that would depend upon the ranges that you shoot at and price range you want to stay in. The 3x9x40 is a very good all-round scope. The best one that I have found for $200 and under would be the Burris FullField II. Lifetime warranty and Ballistic Plex recticle and only one that will give you 95% light transmission. I would not risk my dollars on a BSA, NCstar or any thing claiming to be from eastern europe. There are two scopes for under $100 and those are the Simmons WTC and the new (Bushnell made) Tasco that I would even try. Lots of good comments about Mueller, but I do not own one. I have the Burris right now and also got a 4x12x40 Cabela's PineRidge that I will try on it. If I would not have gotten a verrrry good price, I would not have got the PineRidge. Weaver Grand Slam is also one of the best scopes out there and ranked right with the Zeiss Conquest for low light useability per Outdoor life's comparision panel couple years ago. Bushnell's Legend is also a good scope with about 91% light transmission. Banner's have also been talked about on the boards as being a good low price scope. Stay with a 40 mm scope because the 50 does not increase usable brightness. Pay for a fully-multi-coated scope and high light transmission.
Leopould's are very popular and always talked highly of. But fall short on light transmission: Rifleman approx 86%, VX I 88% and VX II about 92%. I love their warranty, but not the price I have to pay to get it. I would buy a Burris first or a Weaver. You can get a Zeiss Conquest for the same price as a VX III. Check out Opticstalk.com.