What .22 will be the most fun is a matter of personal preference. Usually the one you can hit the best with will be the most fun, but you won't know that until you've tried many different models. My absolute favorite is my S&W Model #41, but they're not cheap these days and a bit on the heavy side for a .22.
I also like my Model #63, Model #622VR and H&R Sportsman 199, it all depends on what mood I'm in that day.
The unfortunate thing is that you're also a Massachusetts resident and you'll notice that your choices are severly limited now due to the AG's "Consumer Protection" regulations. If the gun isn't on the official "Approved Gun Roster", you can't buy it here. I'm glad I got most of mine before the law changed in 98'.