We haven't ever used the dining plan, so can't help with that. But our favorite CS restaurants in World Showcase are:
Yakitori House (me and DD10)
Morrocco place (DH)
UK fish and chips (DD13)
Mexican Cantina (me!)
China CS is good too. Kind of a little bit better than mall food court.
I guess we like almost all of them!!!
We like the pastries in France and always get the strawberry tarts.
Maggie