Michael's in Winnetka is good for somewhat upscale French.
Prairie Grass is probably the closest and gets raves, particulary for brunch.
Francesco's Hole in the Wall is supposed to be the best local place for Italian, but they don't take reservations, so timing could be a problem.
In Winnteka, O'Neil's on Green Bay road is quite popluar, although my meal or two there were entirely forgettable.
Avli Estatorio, a relatively new Greek restraurant in Winnteka is excellent and should definitely be on your list.
For a very casual meal, Mizrahi Grill in Highland Park is well situated and serves very good Israeli food.
Hope this helps. The theater is great by Glencoe itself (my town) isn't much on dining options.
Jonah