It all began with a kiss. Madonna smooched both Britney Spears and Christina Aguilera at the 2003 VMAs after they recreated her infamous "Like a Virgin" performance.
Madonna and Britney Spears' spit-swapping was just the beginning of their collaborations, though. Their song "Me Against the Music" came out right after the VMAs.
Madonna then teamed up with Britney's ex Justin Timberlake in 2008 for the dance song "Four Minutes."
Rivalry? What rivalry? Madonna poked fun at her beef with Lady Gaga by appearing alongside the star in a faux catfight on Saturday Night Live in 2009.
In the most watched Super Bowl half-time show of all time, Madonna performed with cheerleaders Nicki Minaj and M.I.A. by her side in 2012.
At the 2014 Grammys, Madonna appeared during a performance by Macklemore, Ryan Lewis, Mary Lambert, Queen Latifah to help preside over 33 weddings, including those of same-sex couples. She managed to steal the show even in that environment!
Madonna appears on Miley Cyrus' very special "Unplugged" special on MTV... and she even imitated Miley's tongue move! Get your own thing, Madonna.