If the flight is 6 hours or longer for me, I choose business OR first (depends on my stash at the time). If the flight is shorter than that, I go with coach.

I also flew on Turkish Airlines in coach about a month ago (didn't have the miles for anything else - short notice), and had free reign on alcohol. Literally free. I didn't have to pay for alcohol. I also got a little "care pack" that included a cloth, lip balm, etc. I'm sure it was because it was a long flight, but either way it made me feel a little better about being in coach for so long. Continental doesn't provide those amenities for coach on long-haul flights (ie USA to China).