I have two:
For TS, I like Chevy's Fresh Mex at the Crossroads. Yeah, we have Chevy's back home, too, but the one at Crossroads was there before we had them in MD, and there's something about it that's different. Maybe it's the fact that I can look out the window and see the WDW gateway sign. Or the palm trees. It might be the palm trees.
For QS, I've been a fan of Sonny's BBQ for many years. The location nearest to WDW closed down more than 10 years ago, but there is one on Semoran Blvd north of MCO, and I often stop there on my way home.
For buffet, I make no excuses - I like Golden Coral. Yes, it's cheap chain food, but I like it, and I eat there at least once on each WDW trip. Again, we have them at home, but I don't get to eat there often at home, and I never get to eat breakfast there at home, so I will often go to the Golden Coral on US 192 in the Maingate area for breakfast, and occasionally dinner, depending on where I'm staying.