We have been visiting apple orchards yearly since my girls were little and they are now 9 and 11. My absolute favorite is Royal Oak in Harvard, IL. It is well worth the drive even though it is an hour away for me. It is beautiful, huge, and clean. The restaurant has all kinds of homemade food-pot pies, apple donuts, fried chicken, mac and cheese, soups. It has a gift shop, an area for little kids including a train and carousel. They are CLOSED on Sundays so plan accordingly. It is only like $3 per car to get in which I think is worth it because it is such a nice experience and they upkeep their grounds. Normally, I wouldn't pay admission to an orchard because you are buying apples! Check it out!
http://www.royaloakfarmorchard.com/