I got into them because I kept hearing Bad on the radio, and it sounded decent. But when I realized how good it sounded with my headphones I was hooked. All their songs are, just, perfect for my music tastes. Its catchy but the instrumentals are heavier than most pop songs, and Alex's voice. *___*
I'm tempted to say Bad because its the first I heard, but the first that comes to mind is Another Me. Or Temporary Bliss.