Pei Wei makes some amazing fast-casual East Asian food that's super-filling and not terribly unhealthy... and what I really love about them is they'll change up their recipe to your specifications if you want.
Chick-Fil-A is also deservedly popular for its excellent chicken sandwiches and side dishes and clean, friendly restaurants. It's also not nearly as unhealthy as you'd expect since nearly all of their hot food is pressure-cooked (or grilled) instead of deep-fried.
And if you ever have the chance to treat yourself to Fuddruckers' wedge fries, make sure you do it. This chain is stuck in the 90s but my goodness those fries are good. Get some melty cheese and ketchup and enjoy the most delicious potato you've ever had.
We don't go out to eat very often anymore, no restaurants nearby so when we do go out it's not for fast food.
Oddly enough then, my favorite fast food chain is probably Yoshinoya, not even for their food really (beef bowls and curry which are really tasty) but for the fact that outside of ordering your food no one really talks while eating there. It's the coolest thing too, especially when you're a foreigner frequently embarrassing himself by butchering the native language.