Holy crud, I used to LOVE the song "Red Rubber Ball"! Thanks for reminding me of that song... need to go see if I can buy the MP3 from iTunes/Amazon...
Hmm. I think the answer to that question changes depending on the season of life you're in. For me, my song would be this (Single Girls by Laura Jansen).
It's a great song with a upbeat tempo. And the message is just good: wake up in the morning and put on your happy face. Your living, breathing. And in the wake of the earthquake in Haiti, this song just make me realize how lucky I am to live the life I live and I'm still alive and kicking. People around the world face disasters, and have hard lives and sometimes don't live. We tend of take things for granted. This song just make me realize how lucky I am.