Here's a site which may give you some ideas:

http://www.vieats.com/Welcome_to_VIEats.html

Be forewarned, though, that unfortunately it's not being kept up to date as it should be, Just a quick glance shows STT restaurants listed which closed a few months ago!

Shipwreck Landing has been pretty good for lunches and dinners, not fancy but good food.
You can try Miss Lucy's for west indian fare and I cannot remember the name of the fancy place there in Coral Bay or know if it's still open. Maybe some St. Johnians will pipe in.
These are in Coral Bay. Skinny Legs also serves food/burgers, etc. but perfer SL.

Was on St.Thomas about a year and a half back and stayed at Sapphire. We ate in for breakfast and lunch and did dinner out at night. We enjoyed taking the ferry to St. John for dinner a couple of nights. Spyglass was one place we went and had a nice time. My husband loved the view out over the water back to St. Thomas.
We asked a few locals where else to go and they all mentioned Rhum Lines. It was good too.
A friend stayed in Coral Bay just last month and said that Miss Lucy's was her favorite meal out.
On the STT side, down in Red Hook we enjoyed Fish Tales twice during our stay, also had a great pizza night at Island Time Pub and enjoyed Lattes in Paradise for a morning coffee and treat before getting on the car barge to STJ for a day visit.
We had our anniversary dinner at Room with a View in Charlotte Amalie on the recommendation of a couple of locals we asked. Also stopped in at Iggy's at Bolongo Bay one night for dinner and enjoyed it too.
As mentioned, some of these places may have closed since I was there but hope it helps.

Going to be staying in Coral Bay next month for the 3rd time. I like Aqua Bistro and Skinny Legs. Donkey Diner is great for breakfast have not been there for anything else yet but I hear the pizza there is good, will try this trip. Island Blues is also not bad but not sure if they are still open. Sweet Plantains may be the fine dining restaurant people have mentioned. Great local food. Not sure what their status is as they were closed on a Sat night last time we were there.

I'm sure this is sacrilegious, but I'm not really into Skinny's.

However, I'm certainly going to try Aqua Bistro. It looks great. Island Blues also looks interesting.

Does anybody have any Cruz Bay recommendations.

Lime Inn, Sogo's The restaurant up at Gallow's Point and there is one on the hill overlooking the Cruz Bay harbor before the National Park housing that used to be excellent.
Sorry I can't remember the name.

Sorry, I was just thinking earlier that I didn't specify that Spyglass and Rhum Lines are both in Cruz Bay when I posted my earlier response.

Lime Inn is one of my favorite places to go to!

St. Thomas - Oceana for dinner is excellent with wonderful atmosphere!
Hook line and Sinker for lunch - Petite Pump Room for local food.

We were just there, and really liked both the Banana Grill (I think it was grill) and Lime Inn at STJ. We had a nice lunch at the Greenhouse at STT, and good dinners at Enkai sushi, and Room With a View at bluebeards.

Asolare was the restaurant on the hill over Cruz Bay whose name I was tyting to remember.

Are they still in business? Haven't been there for awhile but live in STT and diners in STJ are usually at family's home, then run to catch the ferry.

Lime Inn has the best Hot Fudge Sunday's anywhere in USVI!
I have to have a fix every now and then!:@)

Zozo's at Gallows (expensive, Italian, great sunset view)
Asolare is just out of town near Lind Point (expensive, Caribbean flair, great sunset view)
Rhumblines-very good food, Caribbean flair, nice ambience, must go through a mini market to access)
Lime Inn-good seafood, nice desserts, casual, kid friendly
Banana Deck- next to St. John Jeep rental, known for steaks, good salads, kid friendly)
High Tide - Wharfside Village
Ocean Grill in Mongoose Junction-great food, more expensive

you can look up the menus by google search, restaurant name, St. John

there are many more, ..

Shipwreck is our favorite restaurant and it is in Coral Bay. Do check to see if will be open because when we were there in September it was closed part of the time. We ate there as many times as possible before it closed for a month. The same goes for any restaurant on St John for September. We also like Miss Lucy's and Island Blues. But again, check to see what will be open in September.

Many restaurants do close in Sept. so best to check before you go out to eat whether it is open or not.
This is true for alll 3 islands, not just STJ.