I'm wondering what the preferred FF program is for SJC-based people who don't fly to Asia a lot.

I'm based in SJC (fly out of here 90% of the time, the rest out of SFO) and have been with NW for almost 3 years since I got interested in FF programs(started out because I had frequent trips from SJC to MSP due to family illness and NW was the only airline that had non-stops, and then things just perpetuated so I subsequently focussed on getting my business and leisure miles on NW).

As I don't need to go to MSP more than once or twice a year anymore, I've been wondering if UA or AA (or another FF program) might be a better choice for my needs.

My flying patterns include great interest in 3-4 international flights to Europe (especially Germany and nearby)/year with ability to internationally upgrade; several transcontinentals or US medium haul per year; a couple trips to the Pacific NW (which I do on AS); and unfortunately also a handful of trips to either LAX, LAS, Phoenix, or San Diego on which I can't fly NW or CO or AS to earn miles in the network. I'm also looking at plans for a trip or two to Australia/New Zealand and Chile with upgrades, which are difficult on the NW network. I have no interest in Asia.

I've been considering a change to AA or United given better network connections to where I go and greater international upgrade potential, though since I became elite NW has been quite nice to me and I've been able to secure upgrades with miles on B fares to Europe planning for ahead of time. I also like the idea of discounted WBC Z fares (hope this continues). I don't do a lot of spur of the moment Y fare travel anymore. The upcoming Air France alliance won't likely change much for me compared with flying KLM to Europe.

I can understand why MSP or DTW or Memphis based fliers may prefer NW. But what about you SJC (or even SFO) non-Asia people?