My airline of choice is always BA.
But the finest flight I ever took was Sydney to Johannesburg in Qantas business class. Everything about it was simply perfect.
I'd never consider using a low cost airline. These days, BA is often not a lot more expensive than Easyjet (and is frequently cheaper, particularly at short notice), and I like the comfort of knowing that BA won't cancel a flight and abandon me at some remote location for days on end, as Ryanair might.