The only sit down place to eat is at Sharks Underwater Grill. It's very similar to restaurant at The Sea's @ EPCOT; or the same idea. Not sure how similar the menu's are.
As for QS they have Voyagers BBQ, and SeaFire Inn in the waterfront area; which are my favorite two. I would avoid the pizza place all together; I have never heard anything good about it. There's Mango Joe's with fijita's and that type of food, which is typically really good (just don't go right after a Shamu show, there WILL be a long line. Try going during a Shamu Show to avoid the crowd). And there's the new All-You-Care-To-Eat Italian place, which I don't know much about.
Hope that helps a little!