I have two current favourites, both in .22.
Diana 54 Airking. I picked this up for a song, sidelever works for me where underlever is just cumbersome and awkward. Recoilless, as much power as you want, well built and accurate.
BSA Lightning, early one I got from alanok at the last bash. It was utter dog-poo, but with a very little work it is now a lightweight, compact hunter that still surprises me with it's manners and accuracy every time it comes out of the bag.
If I had to choose just one it would be the BSA
I have, or have had, at least one of everything else, but where most are as good as you'd expect, these two are better.