This survey analyzed average one-way ticket prices (irrespective of distance though).
Average ticket price is based on one-way flights operated by stated airlines. The average prices were calculated from more than 3,220,000 prices of flights operated in the future (June 2014 and later) searched by WhichAirline.com users.
Firefly came out first globally and Pegasus second.
While I'd prefer an analysis incl. all fees and on a CPM basis, this is great inspiration for finding discount airlines I have never heard of like Blue Panorama Airlines, Jazeera Airways or Onur Air.