We're locals, and we have a few favorites.
For oysters, Lee & Rick's Oyster Bar on Old Winter Garden Rd is great. You get an entire bucket of oysters for $16, and they will steam them to your liking and shuck them right in front of you. It looks like, and is, a dive, but these are consistently the best oysters we've had. From the Magic Kingdom, this isn't too far off site.
For fast Mexican-style food, we like
Tijuana Flats. (Click on link for our review). This is a small chain place, but it's good, consistent counter service quality food at affordable prices. It's also good for those looking to eat healthier, since they don't use lard. There is a location in Winter Garden, and also one on Kirkman (kind of near Sweet Tomatoes, if you're familiar with that).
For a fantastic, but more upscale, dining experience, we strongly suggest
Roy's. Again, it's a local chain, but the quality blows away any of the signature restaurants at WDW, with the single exception of Victoria & Albert's. Their blackened tuna is unbelievable, and is extremely fresh. They fly it in every day, so that it was alive that same day that you eat it. It melts in your mouth like butter - I really can't say enough good things about it.
We just went to the
Tiki Bar today, up in Clermont/Minneola. It's a very casual place - well, a tiki bar! The food quality is okay, not great, but the view is unbelievable. This isn't a chain; it's a local restaurant, owned by the owners of the charming Lake Minneola Inn.
If you're looking for a high quality dining experience, you can't do better than to go to West Sand Lake Road in the Dr. Phillips area. The Samba Room there has pretty good food, with smashing mojitos, and of course there is Roy's, Timpano Chop House, and Seasons 52 (at which we haven't yet eaten, but we've heard good things, though it is a chain).
You might also want to go to the Orlando boards; we talk a good deal about local, non-Disney restaurants there. I'd avoid the 192 restaurants like the plague - they're touristy, but, worse, the sanitation leaves much to be desired. Brrr....
Cheers!
Heather W