Hard one to answer. By best do you mean in looks, function, reliability, all of the previous.

The most accurate 22 I have shot was a cheap arse Sterling from the Phillipines. Shot most brands very well. Most would be put into a thumb nail at 50mts. Also proved to be very reliable. I suspect it was a freak. Looks, well that is in the eye of the beholder and in my eye it was plain ugly.

I like the Annies Browning T-Bolt or the old Browning take-down semi auto.