There may still be an active thread on this, but I'll bite. As a professional musician, I have a lot of favorites, but several always stand out when this thread rears its head.
Rocket Man by Elton John. Back when this song came out, I ran around, literally, hanging on to my best friend as he rode his Honda motorcycle. He called himself Rocket man, at the time. To be young and reckless is such a great experience if you can survive it intact.
She Talks to Angles by the Black Crows. I lived through my college years with a sever addiction problem. It was mostly marijuana, booze, pills, LSD and anything I could get to kill the pain. Pain is a universal feeling, especially for those of us who suffered from depression.
Angle Lullaby by Billy Joel. Now that I'm a father and a grandfather, I've realized the importance of family and connection. I love my daughter and I know that not only will I not be here forever, but that she will grieve my passing. I can't be in her life forever, but lullabies go on and on. Pain may be universal, but so is love.
Wither by Dream Theater. The lyrics for this song describe so well the song-writing process, as well as the struggles and fear of your best creations crashing before you at the slightest hesitation. It touches me so deeply as a musician and composer.
Seize The Day by Avenged Sevenfold. This song has a lot of sentimental value to me since I shared it with a very close lost friend of mine.
There are some favorite songs of mine that I could list here:
Desireless -- Voyage, voyage (yes, a French song, but it's all about traveling across the globe and I keep encouraging myself to travel so that I can check out what's there in other countries and islands)
Dragon -- Rain (I play this every time it rains because of the impressive lyrics)
Rush -- Limelight
Solid Citizens -- Singing In The Shower (an Australian song from the 80s; I mean, what's so bad about singing in a hot shower in the morning/night?)
Coup D'Etat -- Dr. I Like Your Medicine (classic Kiwi song, talks about the risks of carelessness, I think)