I take this route annually and would choose KL>VS>AF. AMS is by far the easiest to transit, especially coming from the US. KL is also now all 1-2-1 on that route (either the refurbished 777 or the 787). They provide great service and the seat is outstanding. VS isn't bad. I don't love transiting LHR and the seats, while 1-2-1, I don't find as comfortable (personal preference). AF is 2-2-2, can't stand transiting CDG, and just don't love AF.