The Definition of X: The Pick of the Litter is the first greatest hits album by American rapper DMX. It was released on June 12, 2007, by Def Jam Recordings. Production was handled by Swizz Beatz, Dame Grease, P. Killer Trackz, Black Key, DJ Shok, DJ Scratch, Irv Gotti, Nokio, Self, Shatek King and Tuneheadz. It features guest appearances from The Lox, Drag-On, Jay-Z, Sisqó and Swizz Beatz.

Earl Simmons, known professionally as DMX, was an American rapper and actor. Regarded as an influential figure in the late 1990s and early 2000s hip hop, his music is characterized by his "aggressive" rapping style, with lyrical content varying from hardcore themes to prayers.