A counter service recommendation for lunch in MK and AK, dinner in AK and HS, and also any outside the park suggestions you may have because we do have an off day planned and may not do dinner in AK or HS.
MK - Columbia Harbor House is a must-do if your family likes seafood. In my opinion, it's the best theme park counter service on property. Pecos Bill is another great choice. I'd always heard good things about it, and finally tried it for the first time last week and was really impressed. I'd avoid the nachos, though - they were just okay. The tacos were EXCELLENT and the fajita platters looked great.
AK - Satulli Canteen, no question about it. Excellent food and generous portions. Flametree BBQ isn't bad either. Definitely among the better mass-market BBQ I've had. I also agree with the suggestion from a previous post to hop on the bus over to AKL and give Mara a shot.
HS - Counter service at HS is generally considered a joke. There used to be some great options when Studio Catering Co/High Octane Refreshments, Starring Rolls Café, and the Writer's Stop were still open. But ever since those closed, I've avoided even eating QS meals at this park. Last week, however, we were in HS around dinner time with no ADRs, so we decided to give ABC Commissary a try. I'm still a little shocked as I write this, but I was actually impressed. I had the teriyaki shrimp bowl, and it was quite good. My GF had the BBQ Quesadilla kids meal (she wasn't particularly hungry) and said it was also quite tasty. I saw some folks with the chicken and rib platters, and they looked really nice.
Outside the parks - Wolfgang Puck Express at DS is, in my opinion, the best quick service (actually it's technically "fast casual") option on property. There are a TON of options on the menu, the food is excellent, and the portions are generous so you're getting a decent value. I should stress that by "value" I don't mean "cheap", as it's not particularly inexpensive, but it is among the best bang for your buck in terms of really good quality food and a solid portion.