Personally,
I use an Encore 209x50 and am very, very happy with it.
But, I bought my kids a 20 gauge last year, didn't like the performance w/ buckshot so I bought a rifled, ported barrel for it. One of the ones with the scope mount on the barrel. I bought some Winchester Partition Gold Sabots. Man, this thing reall works well. The ported barrel pretty much eliminates any kick and the boys like shooting it. I put a 3x9 scope on it and it will shoot 2 inch groups at 100 yards with the partition gold sabots all day long.
The 26 grain hollow point jacketed bullet (looks like a big handgun hollowpoint bullet) exits the bore at 1900 fps or so and the ballistics have it 3 inches high at 100 yards and dead on at 150. Now, I would not at this point in my kids life let them shoot at a deer at 100 yards, 80 to 100 is about the limit, but I have shot the gun at 150 and it will put every bullet inside a 4 inch circle. I don't know how much energy it has left at this distance, but I would think it to be plenty.
So far, they have killed two deer with this setup and it really does the trick. Full pass through, great tissue damage and very accurate. Hopefully they will be using this gun for another year or two before I have to get them a .243 or something similar.
BTW, the link for the Winchester site w/ ballistics and performance is;
http://www.winchester.com/products/catalog/shotdetail.aspx?symbol=SSP20&use=7&gauge=2 0

R
Hank