Unlike many of Gucci's other former protegés, Future didn't seem to be in any rush to collaborate with the East Atlanta legend after he was released from prison this May. Almost five months came and went with no new music from the pair (who put out joint tape Free Bricks in 2011), while Young Thug, Migos, Peewee Longway, and even outsiders from Drake to Desiigner, released tracks with Wop. But at long last, and out of basically nowhere, the Astronaut and the Trap God reunited earlier this week on an EP-length sequel to their first collab tape. 

While the slapdash Free Bricks 2 doesn't fully live up to the duo's potential, in my opinion, it is a nice addition to their collab history, of which the tape's first volume is only but a piece. From Future's massive Streetz Calling, to Gucci's Trap God, to Mike Will Made It's Est. In 1989 series, this partnership has stayed alive for almost six years of successful mixtapes. 

They've left behind a trail of indelible under-the-radar gems, and today we're tracking down the five best. Honorable mentions are below.