The first gun I ever bought was a NEF 12 ga. I got it when I was 15 if I remember right from a pawn shop for $56 and a cd I didn't like. (My dad obviously is the one that completed the transaction for me since I was a minor, but I did the bartering with the jerk who ran the shop myself).
I only had two rounds for it when I first got it, both 00 buckshot. I shot both of them and had a bruise for a week. The first full box of shells I put through it where all shot from the hip because my shoulder was still too tender. It kicked so hard that it cut the inside of my finger on the trigger guard.
After I got a recoil pad I shot the thing constantly. Clays, rabbits, birds, couches, cars, refrigerators, microwaves, water jugs, dirt clods, you name it, I've probably shot it with my 12 ga. Despite the fact it's a single shot, it's still one of the funnest guns I've ever shot. It's also the only gun I'd never consider selling, but that's also due to the fact that I wouldn't get hardly anything out of it since they're so cheap new anyhow. Another reason I'll never sell it is because it would be the easiest gun in the world to turn into a sawed off shotgun. (Not that I would ever do it, but just in case that law is ever repealed or I have to fight off zombies, it's nice to know).