Really tough question for me. Unlike some of you, my choices are limited. Aside from DL, which offers the most service at SHV by far, my choices are AA, CO or NW.

In the event that DL disappeared tomorrow, I would like to move to CO, because after DL, I am the most familiar with their FF program (having been a OP Elite for many years thanks to my many HNL-GUM flights). However, CO doesn't serve many of my destinations in Europe.

I've heard lots of good things about AA on the DL board (thanks vasantn), but I know virtually nothing about AAdvantage. I have a pile of AAdvantage miles from the TWA takeover, but I've been on only four AA flights in my life. One predates FF programs (and even deregulation) and two others were Eagle flights. Just not enough experience to really rate AA, but they are weak in a lot of my regular domestic destinations. If the OW alliance could induct another domestic partner (AirTran?), it might be a more attractive alternative.

NW would be my choice of last resort.

Interesting topic and anxious to see what others would do and why.