So at Disney we our faves are the Crystal Palace breakfast, Flame Tree BBQ, San Angel Inn, Rose and Crown, Mama Melrose, Be Our Guest, California Grille (fancy smancy dining), House of Blues (although a blues bar without beer on tap seemed really weird).
Been to a bunch of the Hard Rocks over the years and kinda found them to be "meh"....basically you go to collect a glass from that location LOL.
Flame Tree BBQ-Thunder Falls Terrace (IOA)
San Angel Inn- Antojito's (CW)
Rose and Crown- Finnagan's and kinda Leaky Cauldron (USF), and kinda 3Broomsticks (IOA)
Mama Melrose- Mama Della's at Portofino Bay Resort (currently shuttered), Vivo's (CW)
Be Our Guest- different but still highly themed dining Leaky Cauldron (USF), 3Broomsticks (IOA), Toothsome's Chocolate Emporium and Savory Kitchen (CW)
California Grille- Palm Steakhouse (Hard Rock Hotel), BiCE (Portofino Bay Resort (currently shutttered))
House of Blues- Pat O'Brian's (CW)
Just to give a short run down. Each park has 2 table service restaurants. Lombard's Landing (seafood) and Finnegan's (NYC style Irish Pub) in USF. And Mytho's and Confisco's in IOA. I consider Mythos and Finnagan's quintessential UOR dining. I almost always stop in at the bar at Finnagan's for a quick snack like a Scotch Egg and a Black and Tan. Confisco's is solid but amazingly forgettable. The best thing there is The Backwater Bar. Which is a tiny full service bar with apps from Confisco's.
There are some solid counter service in both parks. 3Broomsticks and Leaky Cauldron have good English/Scottish fare. Thunder Falls Terrace has ribs, rotisserie chicken, and grilled corn. Monster Cafe has Ribs and Brisket. Louis Pizza is theme park pizza similar but slightly better the Rizzo's. Avoid everything in Marvel Superhero Island, Comic Strip Cafe, and Circus McGurkus. The only place I would get a burger in the parks is at KrustyBurger in Springfield.
There is also some great snacks available, the Kabobs and Hummus at the quick service window in the lost continent are great. And as I mentioned before, Finnegan's apps or potato leek soup are great.
CityWalk is really nothing but a mid level dining bonanza. Yeah, just stop into Hard Rock for that drink/glass and keep moving. Toothsome's Chocolate Emporium and Savory Kitchen is hard to describe. Highly themed dining with 2 walk around characters, chocolate in weird things like the bread and my old fashioned. I like the place. Vivo's is Northern Italian where they make their own pasta daily. Antojito's is high end Mexican Street Food. I love the place. 300 tequilas, table side quac service, and did I mention 300 tequilas? Big Fire Grill isn't BBQ. It fire grilled everything but mostly meat. NBC Sports Grill and Brew isn't really a sports bar. More like a Yard House. Lots of beers and some TVs playing only sports on NBC (so mostly taped sports reels). Margaritaville is tropical Hard Rock. Pat O'Brian's blows House of House out of the water in terms of authentically "New Orleans". It is a copy of the original Pat O'Brians in the French Quarter. It's not a blues bar but a dueling piano bar. And no trip to Universal is complete without stopping in at least once for an authentic Hurricane (Pat O' invented them).
There's more, but I have rambled enough. If you have any questions feel free to ask.