What airport depends on what airline alliance you fly with though. I'm StarAlliance so not much CDG or AMS unless it is O/D.
For * A I personally love FRA, but I've been through it 40+ times and know it like the back of my hand. I don't mind the A-B-C pier walks really, and most of the time landing in B and going over to the Schengen gates at A is not that big of a deal. MUC is much nicer to navigate than FRA but the connectivity is not as good.
If you are sticking to * A the new terminal at LHR is not bad, but most of the good connectivity in on BA and taking a bus to T5 and re-clearing security is terrible.
Instead of GVA or ZRH, whose connectivity is pretty mediocre on Swiss, someone flying * A should really look at IST. The Turkish lounge is excellent and the connectivity to EMEA is far superior, and lots of NA airports have a direct connection.
All this just reminds me I have to fly to EWR tomorrow :(