I'd agree that Planet Hollywood is well past its peak.
A few suggestions at DTD:
Rainforest Cafe - the menu is probably similar to PH, but I found the food to be superior. This is also definitely a themed restaurant and it is by no means quiet. There's a "thunderstorm" every 15 minutes or so, so little kids might get a little rattled. My main complaint with RFC is that it isn't cheap, but not much is down there these days. It can also be quite crowded. I'm not sure what the policy on making reservations is these days. Last time I went, I was able to make them thru Disney, one other time I had to call them directly. I've also heard they don't take them, but I'd check that out.
House of Blues - this has become one of our "must do" restaurants. Its located on the West Side of DTD, not far from Cirque du Soleil. We've had some good meals there, but you should probably check the menus.
T Rex - has only been open a few months. Co-workers tell me its quite good and is obviously dinosaur themed. Its run by the same folks that run RFC. It is very popular and loud. Again, I'd check to see what the reservation policy is, if there is one.
Bongo's - This is another one I haven't been to, but people I work with love it. Check out the menu and see if it looks good...