I live in the boonies with little chains, but out of the big national chains Wendy's has the best service, hours and price/performance.
When traveling in the US, Culvers and Whataburger never disappoint for bugers, and for chicken raising cane's and popeyes are good (though latter's service usually terrible).
Zaxbys was super hyped by a few southerns and i found it dry and mid but I'll bring that down to a potential miss.
DQ is as others pointed out underrated for their food but i never think I'm getting a bargain.
I'm too far away from any of the big pizza chains bar Dominos so the ocassional Pizza Hut is a novelty, can't even really knock it.
I'm a big burger elitist and my top 20 is all local or regional bars but Fuddruckers is a good chain burger, not enough locations though.