My son loved the soft squeeze blocks from B. You sold at Target, Fisher Price stack & roll cups that click together to make balls, and any kind of "popper" toy where you press the level down to make balls spin around and pop (we have 'Playskool Explore & Grow Tumble N Twirl').
He still plays with all of this at 16mo and each toy should be under $15.
We've since passed this along to a friend, but it's nice that it stands up in front of a baby and my son learned to spin things and other good hand/eye coordination builders. And as a plus, it has no lights and sounds!