Currently, I'm partial to the following:
To Hell and Back by Sabaton [Power Metal] (It's about Lt. Audie Murphy. If you don't know who he is, drop everything and read up on him right now)
In the Ghetto, Don't Cry Daddy, & Can't Help Falling in Love by Elvis Presley [Classic Rock 'n' Roll] (Going through some girl problems, if you couldn't tell by the last song)
Ain't That A Kick in the Head by Dean Martin [Jazz] (See previous)
Teardrop by Massive Attack [Chill/Down Tempo/Experimental Rock] (Recognizable as the theme to the show House; relaxation song)
Wagon Wheel by Old Crow Medicine Show [Bluegrass/Americana] (Reminds me of home, so it's comforting while I go through a rough patch of life; band is from Virginia, based in Tennessee, and the song is about someone going home to North Carolina, where I'm from originally)
Rational Gaze by Meshuggah [Extreme Metal] (This is my "get big" workout song)
And basically anything by the eternally wonderful Frank Sinatra [Jazz]
I'll be happy to provide links to each if anyone needs them. Except Frank Sinatra, no one should need help finding his stuff, haha.