when Yasin was about 10 months someone gave us one of those cars that they can walk behind and push and later sit on to ride. Yasin still loves it and he's almost 2. At the moment Imran (6 months) loves the peek-a-boo blocks for shaking and trying to chew (his mouth isn't big enough lol) and Yasin loves them for building. There are peek-a-boo balls too. Both my boys love balls. Another lasting favorite is a push along dump truck with some balls in the back that rattle as its pushed. They both play with it.
Some times the best toys are the simlist balls, blocks, sturdy cars.