House of Blues (DTD) - I make a point to eat here at least once every trip. Not only is the food good, but I love the atmosphere! I've never made ADRs. Last time I went (early Oct) we walked right in (early evening). I have had to wait up to 45 minutes (early March and later in the evening). Just grab a chair in the outside area, get a drink at the bar, and enjoy the live music (and people watching).
Earl of Sandwich (DTD) - I was doing my college program in Spring of 2004 when this restaurant opened so it brings back a lot of good memories. Love the bread, the tuna sandwich, and the Early Grey/lemonade!
The Brown Derby (Studios) - My mom and I both have to go here on every visit. We've never made ADRs and have never had longer than a 10 minute wait to get in (always during lunch hours, usually during parade time). Cobb salad and a slice of grapefruit cake. Perfect!
I also have a special place in my heart for strawberry ice cream from Hollywood Scoops on Sunset Blvd in Studios, cheese fries from Casey's on Main Street in MK, and those glazed pecans that you can get at the stands throughout the parks.