In short: the cheapest will be UA
, but you will need to transit in EWR
and thus passing US immigration, which is hassle. Plus, it's a detour. May be an option though if you want to stopover in NYC a day or two...
Otherwise I would go for KLM outbound and AF
inbound. It's only a bit more than with UA
(some 70GBP or so). On the outbound I would rather go for KLM than AF
, due to the fact that transit taxes in AMS
are cheaper and the airport is easier to navigate through (although things changed in CDG
, but still AMS
is way better). But you may as well go for AF
if schedules seem better to you, but try to get yourself at least 2 hours in CDG
to be on the safe side. Some connections offer a bit more than 1 hour, which can be challenging.
On the way back I would however opt for AF
, as KLM's flight will usually have a stop in Curacao on the way, which will unnecessary lengthen your trip. I would personally book KL
exactly because of that, but I am a geek