For me, the iconic thread of Mudcat was and still is the Where is Spancil Hill thread.
I agree with Mick, I don't like lists. They too often are popularity contests, and people and things get left out.
In the Spancil Hill thread, Frank not only came up with Robbie's story of the original version (when I innocently asked Where is Spancil Hill I had no idea what a wonderful history would turn up) but Frank took that info on to add an article to Irish Music magazine after our thread discussion here.
I started talking to Jean Ritchie by email from finding her web site, and gave her the link to Mudcat, inviting her to join. This was in earlier days where there was more focus on music and fewer people involved in the site. It took some time, but Jean (kytrad) eventually joined, and we are all blessed for that. Rick Fielding, Art Thieme, Sandy and Caroline Paton (I'll never forget Sandy and I discussing Mary O'Hara and both racing to the used book web sites to get her autobiography), Bill Sables (and the road trip adventure with Allan C.), and so many more have made this place a rich community for many years. Thank you all for what you contribute!

Alice