I don't have a lot of experience with the newer "adult" air rifles, but with my old Crossman as a kid I could shoot the eraser off of a pencil pretty consistently at 30 feet or so.

I just read an article in "American Rifleman" where they reviewed a couple different models of Gamo air rifles. Accuracy was very good - if I recall it was something like 0.5 inch groups or less. I don't remember what the range was, though - it might have been 15 yards (45 feet). The author was very impressed with them, though, and they aren't very expensive. Check out American Rifleman if you're interested.

2" groups at 50 feet is terrible for an air rifle, in my opinion. My rust-bucket CVA muzzleloader shoots less than 2" groups at 100 YARDS all day long.