I'm looking at AF/KL Flying Blue and LH Miles&More, but haven't yet run the numbers (though my gut tells me Flying Blue, as I enjoy flying Skyteam airlines - AF/KL/DL)
I travel a lot, but am cost conscious. I would not qualify for any status based on revenue, so need a program with segment or mileage based qualification. I value lounge access and a faster check-in queue.