'Hero' I sung that ballad with my class at graduation during 1st grade, I believe. Forgot the exact grade because it was so long ago, but, that was the song that got me into her. Been a fan ever since.
I think I heard "We Belong Together" first, then I remember also hearing "Shake It Off" everywhere Summer '05, then I remember "Touch My Body" or "All I Want For Christmas" next then "Obsessed".
I loved "Shake It Off" but "AIWFCIY" is the first song from her I REALLY LOVED before I stanned. It came on the radio, my mom was singing ha heart out to it, I loved it already, went home and listened to it OnDemand.
I can't remember. I was born in 1993 and I remember knowing she was big in like 1999, so my guess is Heartbreaker or Thank God I Found You. I distinctly remember her Emancipation of Mimi era though.
I feel so old. 
