We went to DeWitt stables for their pumpkin patch and fall events, and it was great for my toddlers.  It's fairly close to the city, and simple with all the right elements of toddler fun - hay rides that leave every second it seems, one of each cute little farm animal to pet, ponies galore, hay maze and pumkins - not a real patch, but the kids liked it.  The people running it were really friendly and family oriented.