Interesting. Of those mentioned in that survey the only two that I have ever eaten a burger at are Culver's and Fuddruckers. That is excluding A&W Restaurant and the bottom of the list staring with Carl's Jr. down. Those I consider places to satisfy a hunger that will not wait to allow a place that serves a appetizing burger to be found.
So anyway Culver's burgers have never seemed that great to me, but Fuddruckers does serve a very nice burger. Quality fresh ground beef and a do it yourself fixings bar. The best burgers I have ever had eating out at a restaurant that could possibly earn the designation of a chain are at Barney's Burger's, a strictly California chain.