10 is a greatest hits album by American Christian rock band MercyMe. Released on April 7, 2009 in commemoration of the tenth anniversary of the band's single "I Can Only Imagine". The album contains twelve of the band's number-one singles from five studio albums as well as a re-recording of "I Can Only Imagine" featuring the London Sessions Orchestra, in addition to two other bonus tracks. Additional content, which varies depending on the version of the album, includes music videos, featurettes, and live recordings.

"So Long Self" is a song written and performed by Christian rock band MercyMe. "So Long Self" is musically a song with a lyrical theme revolving around a figurative breakup with one's self. "So Long Self" was released as the lead single from the band's 2006 album Coming Up to Breathe.