Recaro for me is easily the comfiest, the price was high though so ended up with a DW Cobra Imola, daily it and it's plenty comfortable enough.
Dealt with the cheapo steel framed ones in the past, Forza/Monaco/whatever, generally just very uncomfortable, ok only for short periods, track only! A mate recently got some of the Corbeau club sports, the shell is made from very thin FRP, pretty flimsy and the base bends noticably when you sit on it (im only 70kg). Easy to see why they do not have FIA approval, I also find it pretty uncomfortable, back pain almost straight away.