As noted earlier, Portobello is closed for refurb. Also, I believe Captain's Grill has been temporarily relocated (which is usually not promising) while they remake the concept into a Gastropub at Beach Club.
Here are my favorites at each:
Boardwalk: Trattoria al Forno (good casual Italian), Il Mulino at The Swan (VERY upscale Italian if you're looking for something nice). Big River Grille is nice for just burgers and beers. I have heard excellent raves about the recently refurbished Flying Fish, but have not eaten there yet - have a ADR in November to try it.
Disney Springs: Morimoto Asia (I LOVE the ribs and cocktails), Boathouse (I LOVE eating out by the water), Splitsville USA (shockingly good sushi and bar food for a casual option). There are a number of newer fast-casual places people seem to enjoy that I have not yet tried, including Blaze Pizza, D-Luxe Burger, the The Polite Pig (BBQ).