We have a few of those I Spy type books that are age appropriate, they are great! Every once in a while I get a different one from the library. We have a Leap Frog thingy where he put the letter in the slot and it makes the sound and sings a little song. He likes that one. I rotate a few easy puzzles that he likes and can now do without help, too. I have a few toys put away for `special times`like quiet time or when I need to put Anna to bed; I got them at the dollar store (an etch-a-sketch, a fancy flashlight, etc).
I like those busy bags; let me check my Pinterest when I get a chance and come back with some other links as well.