Have you seen these beautiful blocks called Twig? I got them when Quiet Hours Toys was going out of business and we just love them. The kids like to make castles with stairs (like this picture) and towers and swimming pools. The blocks are really bright colors and can be manipulated and assembled in some unusual ways. The only problem we have is sometimes everyone wants the same blocks, in which case we take turns choosing. And, it works out pretty well for the most part.