Tough call, there are a lot of songs that I enjoy. But to name a few:
"Fireflies" by Owl City
"Everyday" and "Dream Girl" by the Dave Matthews Band
"Every Tear is a Waterfall" and "Viva La Vida" by Coldplay
"Never Have I Ever" by Hot Chelle Rae
"What I've Done", "Bleed it Out", and "No More Sorrow" by Linkin Park
"Feel Good Inc." by Gorillaz
...Yeah, I have a weird taste in music...
Also "Always Look on the Bright Side of Life" from Monty Python. Just try not to sway to the music, I dare you...