Not so much a restaurant but a lounge. I must eat at Hollywood Brown Derby - either the restaurant or the lounge and I must eat at Nomad Lounge. Otherwise, I like to try new places each trip.
Currently, it's Docking Bay 7 for quick service. We've eaten there for every WDW and DL trip we've taken in the last few years since it opened.
My family has historically eaten at Mama Melrose's every trip -- it was one of (maybe the only?) table service restaurant my wife and I ate at on our honeymoon, and it kind of became a tradition for the memories after we started taking the kids. But our last visit was not good at all for many reasons, and everyone has agreed that we won't be going there on this summer's trip.
The number one must-do on the kids' list for each trip right now is 'Ohana.
Whispering Canyon Cafe. Not for the food, which is really good, of course, but for our favorite server, MT. She's a hoot, and a visit with her is always a highlight of the trip for us.
It used to be Tangerine Cafe. But now that that's not an option, we haven't really found another. Although we try for Beaches and Cream as often as possible.
As we stay at Wilderness Lodge more than any other resort, for us it would be Geyser Point and Territory Lounge. We eat there every time we stay at the Lodge, often more than once. But away from there, I guess it's Nomad Lounge in AK and Homecomin at DS. We have lots of other favorites, but they get rotated between trips.
Right now, Steakhouse 71 for lunch. Yachtsman’s Steakhouse & Sci Fi are usually every trip but we have skipped them the last 2 trips to try other places.
I like to try new or different places, and we're at a point where we make few advance ADRs. But inevitably, DH will ask "when" we're eating at Sci-Fi, so I always book there.
Whispering Canyon Cafe. Not for the food, which is really good, of course, but for our favorite server, MT. She's a hoot, and a visit with her is always a highlight of the trip for us.