I see the changing of the show from a story about the group and their dynamics to the Sheldon Show that is what is really killing the show. Some of the best episodes involve the group interacting and each persons quirks contributing to the comedy. The writers have repeated some themes but they now seem centered around Sheldon instead of the group and haven’t been funny. As an example, most people liked the scavenger hunt, so why wouldn’t a group paintball be funny, it could end up with couples against couples or boys verses girls, Bernadette being so competitive and Penny’s shooting experience giving the girls the edge. They could also do another road trip or even for once all go out to dinner together, Penny actually eating with them instead of serving them, I think it would be funny to hear Penny commenting on their service for a change. Anyway the bottom is go back to group dynamics and drop this Sheldon Show path they have now taken up.