For me, due to quite heavy traveling the most important factors are in order of importance:
* Schedules, especially return schedule (evening departure after normal office hours)
* Seat comfort (not necessary seat pitch alone, also noise of the aircraft)
* Onboard service quality in terms of food and the attitude of the FAs.
* If I have FF
Status on the alliance (lounge access).
IFE does not have any significance for me.
Unfortunately my company's travel policy (cheap fares) plays also role in choosing the airline.