For us, HS is kind of a 3/4 day park, so we don't mind escaping for a few hours to get a nice meal. We enjoyed Flying Fish at the Boardwalk, and we're going to try Yachtsman this trip on our HS day.
If you think you will be really pressed for time and really prefer NOT to leave the park, I guess BD would have the best food. We had lunch with an imagineer there a few years ago, so we had the opportunity to try many of their "signature" dishes, many of which we did not particularly care for. I thought the Cobb Salad and the Grapefruit cake were just ok, I don't get the big fuss. Our entrees weren't blow-us-away great, either. My DS, who is not too picky, couldn't find a single thing he enjoyed out of the 4 entrees we ordered. The fish that I had was very good, and DH had filet, which was perfectly prepared, but nothing really special. We were thinking about giving it another try this trip, but DS said "please, no."
We enjoyed our meal at 50's Prime Time last summer. The food was very good, though none of it was stuff I would normally go to a restaurant for, like fried chicken, meatloaf, and pot roast. I make my own awesome meatloaf and pot roast, and I don't eat fried chicken, except at HDDR. If you like those things, their version is very good. Our server wasn't too much fun, so we didn't get yelled at or any great laughs, either. I would have preferred Flying Fish.
We have not been to Mama Melrose since the year the park opened and it was MGM, so I can't comment on that one, except that I know reviews are mixed. We aren't interested in the Sci-Fi atmosphere. We like to sit across from each other at dinner, not side-by-side watching movies and the back of peoples heads. That's just us.