I have too many that I have not yet shot to declare a favorite. Once I've fired them, it will probably be my Henry lever... or my Marlin 25. No, I'd bet it will be one of my Marlin 99M1 rifles. Or, it could be the Glenfield 75. Or maybe...
I do have a 10/22 from 1987 that has been a great firearm. In 2011, I bought into the "tacti-cool" craze and dressed it up with some Tapco gear. It's still a lot of fun at the range, though.
My most impressing .22 rifle, though, is (believe it or not) my Mossberg 702 Plinkster. For the $99 I paid for it new, it is an amazingly-reliable, lightweight little gun that hits right on out to the 25 yards I've tried it to. Haven't been able to get it outdoors to anything further, though. For a great, all-around .22 pack or trail rifle, or even for the person using a .22 rifle for home defense, it's a hard value to beat.