My next "fun" Purchase will be a lever action .357/.38. Winchester and Marlin make them for sure. I have so many .38's loaded up, I want something fun for plinking. And I'll eventually take a deer with it. If you have everything you "Need" pick out something you want for fun. To me it sounds like you have enough shotguns...so unless you're just really into shotguns, then go for something different and exciting.
-Jake