For starters we'd own all their albums.
In cassette *and* CD form. And we'd be singing their top hits at karaoke on the weekends (don't lie). I'm thinking 'Age of Ultron' was their best album, and Civil War is the controversial post-breakup attempt at a comeback. (Fanart by bobbyrubio).
But most importantly....
Remember the band superlatives?
The Spice Girls went all the way with their nicknames (I was the Posh Spice of my friends and I'm proud of it). What would the Avengers' be? GO WILD.