I am a FF with two major airlines, BA and KL, and take around 50 intercontinental and 40 European return trips a year, plus a lot of internal trips in the continental USA.
Sorry, SWA and Delta, but my experiences with US Airlines, AA, UA, NWA, have mostly been pretty average at best.
A lot of that probably has to do with the fact that US Airlines' actual onboard service is either non-existent or compares poorly with onboard service in other parts of the world.
Some of it, lack of onboard product, very poor seating, such as 2-5-2 on NWA DC 10's between AMS and BOS, antiquated aircraft with accompanying lack of facilities, has nothing to do with US flight attendants, but a lot of it has to do with plain and simple bad attitude and lack of interest.
I know North-American, as well as other, passengers can be downright abbrasive and rude, with even well-known, self-appointed gentlemen of the clergy abusing FAs, but the lack of courtesy and assistance from a large cross-section of the FAs I have come across in the USA has been downright shocking !
On my last internal flight, MCO to PHL, the FAs came out of their galley at the back of the aircraft once (!) only during the flight, carrying a large plastic container filled with Diet Cokes, threw one at each passenger, rebuffed all requests for any alternatives and disppeared again.
Some weeks ago, I took a flight from Indianapolis to DTW, all of 25 minutes or so, and all the attending FA did was to give my carry-on bag under the seat in front of me a large kick, "because it sticks out too far". No 'could you', 'would you' or any other questions or niceties, such as a 'please' or a 'thank you'. When I complained I got a big sigh and only when I mentioned the word 'sue', and not in the girl name meaning of the word, did I get an apology.
This is not to say there aren't any excellent and outstanding FAs around in the USA ! It's just that the average FA seems to show a complete lack of interest.
However, I stand to be corrected and look forward to many wonderful experiences in the future.