The best toys aren't toys
For a house with a pair of twins, I think we can be considered fairly minimalistic in terms of toys we have available for them. Simply because we do not have a lot of space.
You might have come across this article by Magda Gerber "The Best Toys For Babies Don't Do Anything", and if you haven't, I strongly recommend that you take a few minutes to read through it.
Toys" need not be toys in the traditional sense. Everyday objects found at home sometimes make the best toys. In our case, I've seen how they really enjoy shakers (small pieces of pasta placed in small milk bottles that would otherwise be discarded), big empty plastic bottles and plastic cups.
I leave you with an excerpt from the article:
What do all of these recommended play objects have in common? None do anything. They will only respond when the infant activates them. In other words our active infant manipulates passive objects. In contrast, entertaining kinds of toys, such as mobiles or later on, windup toys, cause a passive infant to watch an active toy. This trains the child to expect to be amused and entertained, and sets the scene for later TV watching.