Long-term toys
It depends on the age of your child. But there are a lot of popular toys that ride short-term trends. These are often mass-produced using plastics - and destined for a finite life of play. While kids find them really appealing, these "fad" items are not the best investment. Whatever your child's interests, there are probably some more sustainable options - like wooden blocks.
That said, it would be wonderful to see toys like Lego and Playmobil made with recycled or bio-composite plastics. When your child grows out of toys, pass them along to local charities, a doctor's office, or playgroup (as long as they are intact and safe for use).