If we're going to go this route, I would suggest a check inside the box. Something similar to this Font Awesome icon
It's a neutral symbol
It reminds us of voting (inherently political)
It's easy to do
I think custom badges could be a way to further distinguish the site from others in the network, as well as another step down the pathway to moving out of Beta. I suggest that the icon used could be a rosette similar to campaign rosettes worn in some countries.
You set the hurdle quite high. Objectively better in any obvious, major and uncontroversial respect is almost surely impossible because better is mostly subjective and quite often controversial. It probably strongly depends on your perspective.
Therefore I would say that the answer to your question is a clear: No, there aren't any obvious, major and ...