As noted US is now at FAA minimums for FA staffing. Pre-911, our flights were staffed with well over minimums. Other airline crews used to be amazed at how many F/As we'd have... the DC9 and F100 always had 3 while most airlines had 2. The 757 used to always have six, and when they would switch onto a 767 (domestically) they would get a "G", a seventh F/A. Keep in mind the US 757s are configured with eight full size doors whereas other carriers have window exits.
Shuttle flights (727 and A319/320) were always staffed with four to do the "modified pinch" Shuttle service. The 737s would often have a "D", a fourth F/A that was on a different pairing (although Metrojet always had three I believe), and the 319/320 would sometimes have five. The A330 transatlantic, if I recall correctly, was staffed with up to 14 when the service was the best in the industry. I remember being the "K" flight attendant. Its been awhile, I could be wrong... but pre-911 we had very generous staffing and it showed in our service and the subsequent awards from that time.
