I agree with Melissa that fancier places can handle kidz extraordinarily well. I think, but am not positive, that Smith and Wollensky is my kidz favorite restaurant. We have never taken our rather rambunctious daughters to any of the top, top joints, the Tr's, Le Francais or something, but they have been around--Frontera, Hugo's, the aforementioned S&W. I think to a certain extent, children bring their behaivor to the surroundings not the other way around (or did I say that backwards). Put them in the McPlaypen, and they act like McTerrors. Put them in a nice restaurant and they are little darlin's.
The bigger issue, I think with child dining is what to serve them. It's not just a question of will they really enjoy foie gras with carmelized quince marmelade and seared ahi tuna. It's, do you want to lay out a bunch of money on food they may or may not like. So, I evaluate places by what can the kidz eat for not a lot of money. For instance, Carson's Ribs serves a children's steak for about $9. It's certainly more than the typical kids meal, but one daugher, high roller that she is, loves steak (and lobster and stone crabs), and that Carson's steak is an exceedingly great deal for $9 (plus, they get potato, salad and all the chopped liver they can eat). Thus, Carson's to me, is a great family restaurant. On the other hand, there are places, nothing comes to mind right now, where there is just no good cheap option.
Another caution. My kidz love Thai and Chinese food, but not exactly the same foods as Mom and Dad. We actually have stopped going for Thai with them, because by the time we get the satay and mee krob and stuff for them, the night's dining budget is ruined. So, if you want to take your kids to a place where you share food, make sure you like to share the same stuff.
But on the opposite principle, buffets work well. Most of the buffets on Devon, especially my fave, Sizzle India, charge less for kids. Grota on Sunday past charged only $4 per kid.
Rob