Editor’s note: this list was originally published in May 2016. It has since been updated to coincide with the release of “Deadpool & Wolverine.”

In a world before the MCU and the DC Extended Universe (and whatever James Gunn replaces the Dceu with), 20th Century Fox created arguably the first real superhero film universe with everyone’s favorite merry band of mutants, the “X-Men.” Sure, there were superhero series featuring icons like Batman and Superman, but those movies tended to be self-contained. The 2000 “X-Men” films that Bryan Singer directed were the first cape-and-cowl films to eventually spiral into prequels (“First Class”), spinoffs (“Deadpool”), and alternate reality time travel shenanigans (“Days of Future Past”). The franchise wasn’t quite successful at managing this balancing act, and the timeline quickly devolved into utter mush. Luckily, you usually only need to watch a single film to understand it — and there are plenty of them worth experiencing.