We had AAA for years and had no complaints at all. Recently, though, we decided to do a year of Good Sam because we were attracted by the "no limit on calls" thing. (With AAA, there's a place where nominal fees will start kicking in. We never reached that point, but you never know, right?)
We did decide to switch back this year, though, and for one reason: Our coverage with AAA allows for up to 200 mile tow to a destination of our choosing, no questions asked. Good Sam, on the other hand, limits one to "the closest place repairs can be accomplished". Since sometimes we want to do repairs ourselves, we want to keep the option of being towed home, so as said, we went back to AAA.
Side note:
We've never experienced that "at the mercy of the local Club" phenomenon mentioned earlier, so I can't comment on that. I will say that all of our roadside assistance calls have been confined to Washington/Oregon/California- maybe there are regional or other differences in coverage-?