Theres an unbelievable wealth of info in the *A forum and the individual airline sections, but IMHO, it boils down to this:

- for status, Aegean Air. 3000 mi will get you *G
- for Awards whichever airline you fly most often and/or where you plan to redeem your awards

The key is paying attention to what fare class you are booking and making sure those fares are eligible for miles and will transfer.