Whether one prefers DL, CO, UA, or AA perhaps its not necessarily their respective programs you should credit your miles to (although their own elites should have more benefits.) Am based in CDG with C travel on AF and Y travel on AF, NW, and LH. I travel mostly ST and * and have resigned to sticking with AF/KL for ST due to 40k threshold for Gold and ability to earn EQM on their French Amex card. Unfortunately the program is heading downhill fast. I prefered NW program as an Asian based member since it gave lounge access as Gold and had many bonus earning opportunities, but with the merger of DL/NW accounts I'll credit only non-flying credit card/shopping bonuses. For * I'm very happy with BD's program and their earn/burn rates, but this program will probably be absorbed by LH, in which case I prefer UA as an alternative, but maybe there are other * programs I should consider. I'd also appreciate more insight to the best OW program to consider, since there are a lot of interesting fares on BA lately...