Shout Out: Grand Theft Auto IV: The Ballad of Gay Tony
The mission "Corner Kids" chains a string of references to The Wire right in the opening scene.
One mission has Bulgarin's right-hand man Timur accompanying Luis to keep an eye on him. On the way to the destination, Luis tries to strike up a conversation with the gangster, only to be threateningly turned down. Luis' response? '... Total fucking silence...' Try to pan the journey out a bit for the sake of comedy.
Early on, Tony gives Luis an Assault SMG, which Luis describes as "some sci-fi shit." The weapon is basically an A.K.A.-47 of a silenced FN P90, which players might recognize from Stargate SG-1.