Badfish-Sublime
http://www.youtube.com/watch?v=rmadSGJCzo8
This song is almost 20 years old but I know people that are still bumping to it like it came out this morning. Sublime is a legendary band where I'm from, and the fact that this song relaxes me and makes me feel positive is enough to be #1 on this list. I highly recommend Badfish or any other song by Sublime if you just want to be happy and have a positive outlook on life. I have been through a lot lately, and this song has really touched home with me.
The Race- Wiz Khalifa

Another very happy, relaxing song. Wiz Khalifa is known for his laid back lifestyle, and this song captures exactly that. Wiz combines a pretty relaxing beat with some clever lyrics for a really great song. This song has been really popular; it ended up being leaked on the internet a month before it was supposed to, and it still made album, "Rolling Papers". This track is great for anyone who wants an upbeat and catchy song that doesn't do anything but make you grin.
U Don't Know- Jay-Z

I respect Jay-Z at a very high level. He was once a crack dealer in the projects of New York, but later became rapper. He used his rapping to propel himself to being a businessman, and this song off of the first "Blueprint" album really shows how serious this guy is about being the best. Jigga (Jay-Z) is known for his sly and crafty lyrics that depict the hustler's lifestyle he lives. Jay lives for his money, and the words he says in this song show it. The bellow verse is quite possibly my favorite from this song:
"I sell ice in the winter, I sell fire in hell
I am a hustler baby, I'll sell water to a well"
Amber-311

As you can see, I have a wide variety of music. If you guys have any songs similar to these, please let me know.