Well we used to have the choice of Turkish Airlines which were generally very expensive, or good old Cyprus Turkish Airlines. That's a real blast from the past! But in the winter, CTA flew from Antalya and Izmir, not Dalaman. And if I remember correctly, into Stansted.
Pegasus and Turkish Airline flights now are affordable and it is not so bad changing in Istanbul.
Thomas Cook are flying into Antalya, certainly from Gatwick, I think maybe twice a week? But then you have the journey from Antalya, so I prefer to travel via Istanbul personally.