Row, Row, Row Your Boat
Here’s another of those songs that everyone knows, but parents these days seem to forget it can be sung as a round.
Row, row, row your boat
Gently down the stream
Merrily, merrily, merrily, merrily
Life is but a dream
As much as I hate to do it, here’s a video of Barney and his friends singing the round. (Hey, it was the only one I could find that actually had all the real words!)