I had some fun designing a Play set with my 4 year old daughter. This is what we came up with. I will likely add to the collection as she comes up with new ideas. As it is, this set includes a table and chairs, plates, cup and a bowl. All of the items were printed on a MakerBot Replicator Mini with the exception of the table which was on a PrintrBot Plus. The table top is 136 mm in diameter.
No overhangs, Just print them out. All items were printed with a raft. Not sure why, its the MakerBot default and who am I to question success. The gap for the fittings are .2mm. On the Replicator and PrintrBot, this produced a friction tight fit. Depending on your printer you may need glue or sandpaper.