I had the opportunity to maintain https://bitcoin.org/ for a few years. I'm proud that in that time I was able to help a bunch of new people all around the world learn about and get starting using bitcoin.

At the same time, it was difficult working with the domain owners behind it who at times were self-serving and very ad-hoc with respect to wanting to push their own agendas.

So definitely one of my most proud projects, but also bittersweet. :/