The kids love the fries and if you ask for an order as soon as the waiter takes your order, then you can start shoving food in their mouths early.
Free balloons when it is over, and they are very pleasant about getting a kid their favorite color.
Endorsements and warnings of local businesses that are family friendly/unfriendly. We have a family of 6, 4 girls ages 4-17, so we do get a wide range of experiences in the Harrisburg, PA area.