i couldn't pick just one to be my favorite, since these 4 have important meanings for me, so yep on 1st place there's a lot

• story of my life + best song ever + history + night changes
• drag me down
• little things
• one way or another
• kiss you
• you & i
• what makes you beautiful
• live while we're young
• midnight memories
• one thing
• gotta be you
• steal my girl
• perfect