It doesn't really have any specific lyrics I love or think are especially inspirational, but I find it a happy, uplifting song.
The world's biggest flash mob all dancing together to the Black Eyed Peas singing I Gotta Feeling on the Oprah show a few years ago:
(the good bit starts about 1 minute into the video, but this was the best HD video I could find)
(Again: I don't own any music/ videos etc. All linked to Youtube and artists accredited)
“Behave so the aroma of your actions may enhance the general sweetness of the atmosphere.”
~ Henry David Thoreau