Like many has said, the best FFP varies from person to person. Some say it's the redemption, others say awards, etc. etc...

I choose AA because of the potential longterm benefit of elite status for life which is based on total miles one earns from all sources of miles (hotel stays, rental cars, credit cards, elite bonus miles, online shopping mall, dining, etc.) not just BIS flight miles like most others FFPs

That's my current goal right now - to get to 1 million total AA lifetime miles in order to get AA Gold status for life, which is equivalent to becoming OW Ruby status for life.

After that will be achieving 2 million total AA lifetime miles which will get me AA Platinum status for life, or equivalent to being OW Sapphire for life. Once I get there I will then have business or first class check-in, ability to reserve better Y seats, lounge access across all OW carriers for life!