No offense to the folks over at Discourse, but the default forum layout could really do with some polish. I personally find the comments section requires an uncomfortable cognitive load to read at times. What started in my mind as a simple CSS user style to adjust the legibility of the text and spacing between comments has evolved into a more focused effort on my part to make the site feel more familiar and at home.
Right now my user style does its best to make comments and posts resemble comments on GitHub. I chose GitHub because their site has always struck me as polished and well thought out, while not being too fancy. The source can be found here. If you're not familiar with how to use this CSS yourself, you need a browser extension like Stylus to use it.
I would love to see this grow into a more complete theme for the whole site, but I don't have the time to do much more than this myself.
Forks, PRs, feedback, and suggestions are all welcome and encouraged! Let me know what you think.