If you're anywhere near the western suburbs, you might want to check out the Sunday brunch with Santa at Foxfire at the Stone Barn, just outside Kennett Square. http://www.thestonebarn.com/holidays.htm Complete your day with a visit to Longwood Gardens while you're in the neighborhood.
We went to the Elmwood Zoo brunch last weekend and it was very nice. Huge brunch buffet with carved beef, omelet station, waffle station, fresh fruit and veggies, mimosas, etc. The Santa is great, they have live reindeer, elves, etc.