The first Panda 1.0 site at Google forums.
I ended up looking at the first couple pages worth, it's pretty interesting. For starters, around half the sites that reported being penalized weren't, they just saw a big shift in their keywords and assumed it was a penalty when it was the algorithm shift part of Panda. Several of those sites were in the top couple thousand on Alexa and have seen nothing but traffic increases since. They were primarily community based.
On the other hand, there were another bunch of high ranking sites on Alexa that got hit in the first two Panda's and haven't done anything since. Then there were a couple that recovered at various times and stayed up. Whether they recovered due to making changes or whether they came back on their own like my hobby site isn't clear since it's hard to find comparisons in the Internet Archive for large sites.
Now that I think about it, I should have started by finding an pre-Panda for each in the Internet first, and than looked for it on the current site. I'll have to try that later when I have time. If it looks useful, I'll post the results here in a new thread, but I suppose I'd have to do it without domain names.