I haven't flown with BA a lot, but the flights I have had I can't find anything to complain about. They didn't wow me but they didn't disappoint me either. The crew were certainly friendlier than the ones I have experienced on other airlines apart from Thai Airways. Miles above Thomson who apart from a couple of cabin crew, can barely raise a smile and seem annoyed to be there.
I know it's a simple thing, but I like that either the Captain or FO stands by the door and greets you in and out with BA. It's nice to see who is flying you and he was really polite and seemed really enthusiastic and happy when i got chatting to him about our flight and aviation in general.
I've only ever flown shorthaul with them, but the experience was quite pleasant.