Pegasus is the Southwest Airlines of Turkey. I flew them from Istanbul SAW to Tbilisi TBS last year - newer planes, but it's an LCC. I don't think I'd want to travel too far on Pegasus, but it's a very well run carrier. They've been expanding like hell the past few years. Look them up on Wiki - I believe the president of this carrier is a woman.

Only downside to Pegasus is the spamming in Turkish - had to filter them out of my emails