Umm, it's Nobody's Home. But voted for I'm With You because that's also great. Everytime, Innocence, Because of You and The Harold Song also slay my life .
I would say Everybody Hurts but I don't know it counts as it gets somewhat upbeat with the drums.
If Sia becomes a pop girl then we have the new queen of ballads "Don't Bring Me Down" is so amazing and heartbreaking.