Where is the best place to buy education game/book for preschooler in SG?

Bookstores like Kinokuniya carries pretty good educational material for preschoolers. Some of the books in stock mixes the best of both worlds -- toys and books -- in the form of interactive books (usually with audio, visual and sensory features). Another suggestion would be Popular Bookstore. That is the traditional go-to place for educational materials when I was growing up and from what I remember, I think that the selection for pre-schoolers are pretty good too.