I like the service and also to be on a British airline - makes me feel good coming home!
Happy to use LHR, LGW or LCY - rather vital for BA. Need to travel to MAN and NCL often-ish. Pity BA doesn't do Northern Ireland as I need to go there too.
I trust its safety and its staff and their training. I like 'full service' - a 'free' drink, at least.
But mostly like having status which comes through loyalty. ^
My first long haul flight was to IAD with BA back in the days of big screens (the film was Rocky, so that dates it!). Still a nationalised industry then I think - just. One of the items that came on the onboard screen pre-film made a big point out of 'To Fly to Serve', a principle which I liked. So that hooked me too. I wish they would make more of that now.