One of my favorite Raffi songs is Willoughby Wallaby Wee, an elephant sat on me, Willoughby Wallaby Woo, an elephant sat on you (http://new.music.yahoo.com/raffi/tracks/willoughby-wallaby-woo--764614). This is a fun song because you can make up funny rhymes for the names of your children or anyone in your family. It's a great way to teach and reinforce rhyming words, which is a big help in teaching your child to read.
I like to sing this song with my grandchildren. I rhyme the names of their cousins, aunts and uncles and feel like I'm helping them keep connections with their extended family.
This is also a fun song to sing at school. We do it with the children all standing around holding onto a parachute. When the name of the child is rhymed, they get to run under the parachute and come out on the other side. If you don't have a parachute (and why would you?), then use a tablecloth or bedsheet.
Any other ideas?