My favorite of all time actually came not in First Class but as I was preparing to board. Delta called Business Class on my flight from LHR and I started to walk to the boarding gate. One woman who apparently had appointed herself "gate monitor" lashed out at Me "THEY ARE ONLY BOARDING BUSINESS CLASS, GET BACK IN LINE" (yes she screamed it so that most of the gate area could hear her
) I smiled nicely and said "I am in business class would you like to inspect my boarding pass". She made some nasty comment and her poor traveling companion looked like he wanted to crawl under the plane with the luggage and said "SHUT UP" LOL!
At the time I was much younger and I guess she thought young females weren't allowed in the front of the plane!
I generally don't recall hearing many comments besides from my coworkers when I got upgraded and they didn't...
As for judging on appearance. I am reminded of the car dealer in Nashville. I was rear ended, my 9 month old car totaled. The next day in shorts and a t-shirt I go to the Saab dealer to start the process of buying a new car. I walk around the cars, I look at the cars, I am probably in the dealership or parking lot of well over 20 minutes. I can see the salesman, they are all doing nothing.... I leave and go online and buy the car in another city. When I go in for service, I find the manager. I say "see that new 9-3 convertible, all anyone had to do to get that sale was talk to me, but apparently women dressed in shorts don't buy cars". In the immortal words of Julia Roberts "big mistake!" Easy sale gone. He at least had the good sense to apologize and act embarrassed.