Ask HN: Where do you find airfare special deals?

The web is full of fragmented info about special airline ticket deals, there are tens of blogs and forums that publish these offers.

I'd like to round up the most common places people check (forums, communities etc) into a public spreadsheet, so everyone can use them.

Let's leave the ticket search engines a side at the moment and focus on deals that are found by enthusiasts and published on the web.