We've eaten at the Crossroads of Lake Buena Vista 'Pebbles'. It's a local chain with about 5 outlets and gets rave reviews, but we were a little underwhelmed. I'm not quite sure what all the fuss is about, but I've never read a poor review (here or elsewhere).
The Whispering Canyon Cafe seems to be loved and reviled in equal measure. As you probably know, it's at Disney's Wilderness Lodge (post a thread on the Disney Restaurants board, but don't expect to be any more enlightened!) We ate there for the first time in May. It was worth it for the glorious trip on the water taxi from MK to WL (dh and I were the only ones aboard). The food, cleanliness and entertainment were just OK, in my opinion and I probably won't be going back, but I'm still glad I've done it - another to cross off the list.
We haven't tried the others on your list, but here's what I know about some of them:
Bubbalou's Bodacious frequently wins 'best BBQ' category in various polls. There are 3 locations.
Samba Room and Melting Pot are both on West Sand Lake Road near Universal Studios. The whole area is buzzing with new shops and restaurants. Others in the vicinity are Ruth's Chris Steakhouse (a new discovery for us - far more upmarket than its unassuming exterior belies), Thai Passion, Moonfish (seafood and sushi) and Seasons 52 amongst others.
Other suggestions? There are now so many fine restaurants in the Orlando area. We love eating out. What kind of thing are you looking for? Some of our current favourites are:
Emeril's Tchoup Chop (at Royal Pacific Resort at USF);
All 3 restaurants at Gaylord Palms (on Osceola Parkway) - Sunset Sam's Fish Camp (not surprisingly, seafood), Old Hickory Steakhouse (expensive, but way exceeded our expectations) and Villa del Flora where we enjoyed a great lunch. It's a buffet which we don't normally rate highly, but this was fresh, with a great selection and at a reasonable price;
The Palm at Hard Rock Hotel - suberb steaks. Their house specialty is surf and turf (steak of your choice, plus Jumbo Nova Scotia lobster);
Boma and Jiko at Animal Kingdom Lodge. Boma is the surprise choice here for me being a buffet. Breakfast on our first morning is fast becoming a tradition!
The Cheesecake Factory at the Mall at Millenia. A gargantuan menu with something for every taste. And cheesecakes to die for (we get them to go - the entrees aren't small!) We also enjoyed lunch at Brio Tuscan Grille (Italian) and we've yet to try McCormick and Schmicks and PF Chang's (poll winning seafood and chinese respectively).
California Grill at Disney's Contemporary Resort never fails to live up to all the hype, and we also enjoy Flying Fish Cafe at the BoardWalk.
I could go on, but I'm getting hungry!