While AA certainly is not what it was under Fang, I think it is much better than it was 10 years ago. Like any big company, I find the staff and customer service depends on the individual, but on average I think it has gotten exponentially better. It has a newer fleet than most other airlines, and I like both the in-seat and mobile entertainment options. Similarly, my flights are on time much more than they are late (in transparency, all airlines have added superfluous block times). In terms of AAdvantage, its biggest mistake was promoting MileSAAver, which almost always disappoints, as opposed to marketing AAnytime and using MileSAAver as a pleasant surprise. In fairness, I think most of us take flying for granted and forget how complicated it is both physically and logistically. I think the biggest problem with air travel is other travelers vs. the airline. If most of use followed the rules and showed a modicum of courtesy, it would be a better experience.
All that being said, I prefer WN and even have had a couple of decent experiences on NK. I never fly UA, DL, or B6.