S&W 15-22's are great. They are made almost entirely of plastic, but still don't feel "cheap".
I picked mine up used, so have no idea on what the actual round count is, but I've put around 3,000 rounds through it in the last few weeks, and it's been perfect.
The only downside to them now, is you'll likely pay through the nose for mags, and finding ammo can be challenging at times. Mags were $20. Now, I frequently see them for $50 - $70.
The only thing that mine MIGHT be replaced with, is a dedicated .22 AR (as in, using a real AR lower, upper, etc).