Most Known Unknown is the eighth studio album by American hip hop group Three 6 Mafia. It was released on September 25, 2005, and is the follow-up to the 2003 album Da Unbreakables. This album is known for having some of Three 6 Mafia's biggest hits, including "Stay Fly" featuring Young Buck and 8Ball & MJG, "Poppin' My Collar" featuring Project Pat (though Pat's verse wasn't included in the first edition, but would later be included in the re-issue) and "Side 2 Side" featuring Bow Wow and Project Pat (with Bow Wow and Project Pat's verses, like the "Poppin' My Collar" remix, would not be used in the first edition, but would be released in the re-issue, along with another remix featuring Kanye West and a slightly different sounding melody). This album would prove to be their biggest succes