Caractacus Pott : Frankfurt is a good airport to go through. For some reason, though, Lufthansa doesn’t stop in Frankfurt anymore from LAX to Switzerland - instead they have you go through Munich?!?
Heathrow is OK. I did learn my lesson once though when booking flights - look carefully at the airports, not just the city! On our last trip to Switzerland we landed at Gatwick and the next flight was leaving from Heathrow. I just saw “London” on the British Airway tickets and didn’t pay any more attention than that.