Okay, nostalgia aside, my favorite for a semi-auto that I can "play" with, modify, and is super accurate is by far the 10/22. There's so many things that you can do to them. And, rig one out and take to a steel challenge match and you'll have a ton of fun.
They are super simple to tear apart, work on, replace this or that. I've got several that the only thing "factory" is the receiver housing, ha. That's not to say that they won't perform very well completely stock, I just like to tinker.
