Kind of a broad request, but I'll take a stab at it...If you are talking about a springer, (single shot break barrel), then I'd go with the Beeman R9 in .20 caliber. Around $400.00 I believe.. I bought one from Pyramyd Air a few years back and slapped a cheap 3x9 MilDot scope on her. Like most Spring guns, its hold-sensative, but once you master the "Artillery Hold" (Google it, it will restore your faith in spring guns)..That rifle will shoot a 10 shot group I can cover with a quarter, easy, at 30 yards. Powerful enough for squirrels , pigeons & crows, but thats where I'd stop.
If you want to take it to the next level, try a PCP (pre-charged pneumatic) gun. You will need a high psi air source like a pump or SCBA/SCUBA bottles, but once you cross that bridge, you won't come back....Not recoil sensitive, much more powerful & as accurate...I have a PCP rifle that shoots heavy .22 cal pellets (18+ grainers) at over 900 fps and can cover 5 shots with a dime at 50 yds.. Its my "chicken coop rat rifle" and its a hammer for sure..
All depends what you wanna do (and how much $$$ you're willing to spend..). The Beeman being $400 and the PCP rifle being $1500. Although you can get a great lower priced PCP in the form of the Benjamin Marauder. They run under $500. but for all around casual fun, I'd go Beeman R9. State of the art Rekord trigger, beautifully finished and reasonably priced. 20 cal. pellets are all over the place and they are a good compromise between the 177 & 22. (my R9 does about 825 fps with standard 20 cal pellets ..high 700's with Crosman Premier heavies (14.3 grs.) Rifle is factory stock.

Last edited by ds1911; 06/07/14.