Ask HN: Where is the best place to sell going concern websites?

I've looked at sites like http://flippa.com but to be honest it looks a little full of dubious users and slightly more dubious sites for sale. If I was looking to sell successful projects of mine. By projects I mean sites that are going concerns that to be honest dont interest me that much anymore, that is not to say that they aren't good or growing, just that I've moved on.

Where's the best place to do that? or is there even one?