Of the ones already noted, I'd +1 for:
Garden Grill
Boma
Whispering Canyon (better food and cost than LTT, imo)
Biergarten, especially if you love meat (and beer) but there are good options for vegetarians too, believe it or not.
Liberty Tree Tavern is fine - but also the food is not really any different/special from many American restaurants on and off site. Then again, you're in MK and the theming is great. (I grew up in MA so maybe that's why I'm sort of meh about this place with no real reasons to give it a thumbs down)
Cape May Cafe is great if you like seafood - which I do - but even so the scent of seafood in the area could be off-putting to some. We have gone for breakfast and enjoyed it.
A sleeper which I love (and on the Skyliner):
Sebastian's Bistro at Caribbean Beach Resort. dinner only. Prices are quite good for all you can eat, the food is a little different, and it was a nice walk from Riviera. (I think the walk from Riviera skyliner is about the same as the one from CBR's station; we walked along the lake from Riviera which was pretty.)
I would recommend doing a breakfast AYCTE/buffet meal. They tend to be easier on the budget.
My parents used to do this at the buffets in Las Vegas - book the latest breakfast ressie and stay on for lunch. I don't recall whether this is still the case at WDW (that breakfast and lunch prices are different), but even if they are the same, it's usually still a discount from dinner. If you're traveling at a hot time, as we have often done - you can rope drop, get some park time, and then break for brunch right when it starts to get hot and crowded. fill up and then you may be ok until dinner, or just need a few snacks here and there. My faves for brunch would be:
Boma at a resort, and
Tusker House in a park.
For a splurge:
Artist Point at Wilderness Lodge is also solid. I can't tell if "food is their love language" pertains to quantity, quality, or both. The food is a notch above most character meals in quality (and I think they will bring you more, but I haven't tested it) and the interaction with the Queen is one of my favorites. But it does come at a steep price.