A memorable moment was when they both participated in the scavenger hunt. They showed great teamwork and competitiveness, which was really fun to watch. They were able to use their different skills to try and win the hunt.
One interesting story is when they first met through their mutual friends in the group. Penny was initially a bit more outgoing and worldly compared to Bernadette, but they quickly found common ground in their love for their partners and their shared experiences as women in a group dominated by male scientists. For example, they often teamed up to give advice to Sheldon when he was being particularly difficult in his relationships.
One interesting moment is when they participate in a double date together. Their different personalities and the way they interact with their partners create a lot of comical situations.
There was also a time when they went on a girls' night out together. They shared secrets, laughed a lot, and had some really deep conversations about their relationships and future plans. It showed how close they had become as friends over the series.
Another great moment is when they participate in group activities together with the guys. They add a different dynamic to the group, and their friendship helps bridge the gap between the nerdy guys and the more social girls.
Their ability to grow together is another positive. At the start, they had some differences but as the series progressed, they became closer and more understanding of each other. They learned from each other's strengths and weaknesses, which is a great example of a healthy relationship.
When Penny got a small role in a local play, Bernadette was the first one to offer to help her rehearse. She gave Penny constructive feedback on her performance, which helped Penny improve and gain more confidence in her acting abilities. In return, Penny would encourage Bernadette to stand up for herself at work and demand the recognition she deserved for her scientific achievements.
Penny helps Bernadette to be more outgoing and relaxed. Bernadette is often quite reserved in her work - dominated life, but Penny drags her into more social and fun situations, which broadens Bernadette's social skills.
Another aspect could be Penny's family. Fanfiction could explore what happens when Penny's family from Nebraska visits and how the guys interact with them. Maybe there are some comical situations where Penny's parents misunderstand the guys' scientific work, and Penny has to mediate. These stories can be really interesting and family - friendly.
As far as I can remember, there is no such Penny wedgie incident in The Big Bang Theory. The series was filled with different kinds of comical situations. For example, there were Sheldon's idiosyncrasies, Howard's attempts to pick up women, and Raj's selective mutism. But a wedgie incident for Penny just doesn't seem to be part of the storylines.