Battery-free toys are usually open-ended in nature and invite hours of good old-fashioned play time. On top of that, your home will probably be a lot more peaceful.
I really have to agree with the list that Frugal Family Fun came up with, drawn mostly from her readers. Most are basics that haven't changed much since we were kids like:
• Play Dough
• Play Kitchens and food
• Train Sets
• Doll Houses
There were a couple surprises including Homemade Cleaning Sets and something called Homemade Poi from New Zealand. Head over to Frugal Family Fun for the whole list and resource links.
Though they're not toys in the traditional sense, I'd add art supplies, books, musical instruments, and sensory boxes to the list. My daughter can often be found asking to do "an art project," reading a book to her "amamals," or sorting through a giant bowl of rice with a bunch of measuring spoons and cups.
What are you favorites?