The Mysterious Mare Do-Well

Personally, this one was my least favorite in the series thus far. Why? Because the girls, minus RD, were assholes. They didn't talk to her about not being a showboat. Instead, they talked about her behind her back, went as far as to make up a hero on the fly to upstage her at every turn, which led RD to a minor form of depression where she felt so alone that she rejected to spend time with Scootaloo. In the end, they all basically quoted the moral of the story, not allowing RD to figure it out for herself, which led to her almost going back to being a showboat.

Story and moral wise, this episode was the weakest out of all of them.

Reference wise, this one was over the top with Darkwing Duck, Spiderman, and Batman all being referenced in some way:

Darkwing Duck - Mare Do Well's costume design
Spiderman - RD saying, "No need to fear, your friendly neighborhood Rainbow Dash is here!"
Batman - The posters at the event at Town Hall show a similar design to the Batman comic cover.