Virgin. After our last trip with BA where our 8pm flight was delayed for 24 hours, but they would only tell after 12 that we were allowed to go home / to the airport hotel they offered, I will not fly with BA ever again. It was terminal 5, so after 11pm all coffee shops etc was closed. There were crying children, old people, people in wheelchairs, and all they offered (exluding hotel in the end) was a £5 food voucher per person. Being terminal 5, there were no other lounges, yet they refused to let even assisted passengers in the BA lounge "without proper tickets" (one BA staff member's words!) (i.e. Business / First). Anyone wanting to leave before the final decision was available (that they would only be flying the next evening) were told that they would lose their money should BA decide to fly that day after all. You were not even able to volunteer for a later flight. Oh, and when people tried recording the rudeness to passengers (this was 11pm) on their mobiles, they were told that police would be called to escort them off the airport. Police later arrived anyway, but they were great in chatting to people and trying to keep people calm. This was in March, and the reason given was that an unusual number of their planes have recently broken - something like 5 in the last week - and therefore people should understand that, with technical difficulties on our plane, they had problems finding another plane to replace it.
Sorry, I'm ranting and clearly still very annoyed, but I cannot get the rudeness and attitude of BA personnel out of my head! Things happen, planes break, but such a high number indicates maintenance issues, imo. Actually, even if you ignore that, if they treated passengers better and communicate more, the situation wouldn't have gotten as bad as it did.
Fly Virgin. They strike less and are generally friendlier. Of course this attitude doesn't include everyone, and I've been a regular BA customer for years, but enough is enough.