You might want to consider Quince in Evanston (at the Homestead Hotel). I haven't had an official meal there since Andy Motto took over the kitchen, though I was there for a wedding reception at which the food was quite good. In any event, it is a bit fanicer than some of the other places that have already been mentioned above, is technically in the northern burbs and we've brought our son there many times.
Another place that might fit the bill is Restaurant Michael in Winnetka. I personally don't love the place, though it definitely has its fans. That said, it's certainly fancy and chef-driven (Michael Lachowicz), and our son did very well there.
Lastly, Le Titi de Paris in Arlington Heights might be what you're looking for. It's fancy but the vibe is friendly and the food is very good.
The bottom line is that if the kids are reasonably restaurant-savvy, any of these places should be fine. If not, they're probably all best avoided. While all three are extraordinarily accomodating, if the kids aren't happy, it won't be pleasant for you or anyone else in the dining room.
=R=
Quince Restaurant (in the Homestead Hotel)
1625 Hinman Ave
Evanston, IL 60201
(847) 570-8400
Restaurant Michael
64 Green Bay Rd
Winnetka, IL 60093-4006
(847) 441-3100
Le Titi de Paris
1015 W Dundee Rd
Arlington Hts, IL 60004-1419
(847) 506-0222
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