I give the boys tupperware in the kitchen sink, they pour, put lids on & take off, make me dinner etc - not sure what the educational value is, but it keeps them out my hair for a few minutes.
We count lamp posts when in the car - do it block by block, otherwise the numbers get too high.
Play dough is great - I have a wonderful flop proof recipe if you need it
Colouring in
A bucket of water and a bucket keeps them busy outside "painting the paving / walls / windows - once again, not sure of the educational value, but there must be something there
Puzzles - tho my patience levels don't always allow this (i am a bit too much of a control freak)
Reading - but once again my tolerance levels only take so much of the same book over & over in the same hour
Painting - an outside activity in our house
Glueing - cut pics out of an old magazine, paint a piece of paper with glue and let LO create
Stickers and stamps - as above
A mud patch in the garden is great fun (for them)
A bucket with various objects to "experiment" eg what floats and what sinks and why. It amused Brandon no end to find that some things float when empty, but sink when full (an old juice bottle)
Different textures eg flour, sugar, oats, sand, jelly, pasta etc - can also be sprinkled on a paper with glue to make artwork
Ball - kicking and catching with develope eye / foot / hand co-ordination.
But remember even normal playing is educational for them, they will learn or develope physically even from running around under a sprinkler - eg if it is one that turns, they learn about timing and dodging the spray, so sometimes it is good to just follow their lead.