It kind of depends what you are looking for.
Marrakesh is our traditional favorite restaurant. The food is really good and its rare to get good Morroccan food in most cities (we have a few places here - and we've been to some of them). The atmophere is a little quiet, the food slightly adult (although this is a good place to take kids). The belly dancer is great. Morroccan is easy to cook at home - couscous is one of my favorite foods.
Teppanyaki is a fun experience, but its difficult to talk. The kids really enjoy Teppanyaki (they are 4 and 5). There are Teppanyaki restaurants locally, but we don't tend to go out of our way for them, which makes the one in Epcot more special. Teppanyaki has great scallops and beef though - barely seasoned, served off a hot grill. The entertainment is the chef - and they do a great job. I find Teppanyaki type food to be harder to make at home (I can't get a grill that hot!)
If I could only do one, if it were just me and the hubby, we'd choose Morrocco. I'd take the kids to Teppanyaki.