My family's favorite TS option at DHS is the Brown Derby. We went there for the first time on our last trip and we plan to go back on our next trip. The cobb salad was our favorite.
We used to go to Sci Fi and it was pretty good. It was fun to watch the bad sci-fi movies as we ate, but haven't been in a while.
Went to Mama Melrose once and I can't really remember anything about it. For me, that usually means it wasn't great, but it wasn't horrible either.
Been to 50's once, but it wasn't our thing. Didn't really like the servers pretending to be Mom/Dad. As a child, I got enough of the "mind your manners at the table" and "eat your veggies" at home that I didn't really want to be reminded of it on vacation. Some folks love it, but not me.
In terms of CS, some of my family liked the ABC Commissary. It had a pretty good variety of items.
Starring Rolls (if it's open) has really good cupcakes. Probably not a really healthy meal, but the cupcakes are really yummy!