I found this little gem awhile ago on Pinterest and my kids have loved it.
It does require a little bit of planning (or buying bread/milk tags) but was free and fun.
I started collecting the bread tags off of english muffins, bread, buns, sometimes potatoes or carrots (milk too if you live in an area with bagged milk) when b was only a few months old. I finally had enough of a stash (and felt confident enough that b wouldn't immediately put them in her mouth) to let them play with it.
It is literally just a clean, empty yogurt or sour cream tub with a hole in the lid and the object is to have the kids pick them up one at a time and put the bread ties back into the container. Not exactly earth shattering rocket science here, but it is a game both of the kids really like. b actually sat there for about 25 minutes picking the ties up, putting them into the tub and requesting to dump it out and start again and again!