So I suspect that my opinion will be in the minority here, but I will maintain that the value I get out of my AMA membership is exceeds the cost of my dues. This is a very subjective opinion and I will grant that many here would not see it that way. I respect those opinions.
Why do I find value? Because I like having a nice place to fly. Many will point out that this is due to the efforts of the local club and not the AMA. Again, I respect that opinion and understand the perspective, but I also believe that without the framework of the AMA, it would be much harder for local clubs to exist. Empirical evidence tends to support this notion since nearly every flying club is AMA chartered (at least the ones I am aware of). If there was a non-AMA field that was successful, well run, organized AND offered insurance without requiring an AMA membership, I would consider joining. Per one of my previous posts, I have heard rumor of such sites, but I do not know of any active in my area.
Could the AMA be more effective and efficient in its mission? Certainly! But simply put, the AMA membership is path to getting me what I really want, a well run, well maintained, insured, and pleasant place to fly. I know of no other vehicle to obtain that, so I am happy with the value I am getting.