I personally consider the apex of X-Men to be Claremont's whole run from the mid-seventies to the nineties, House of X, E is for Extinction, all the usual hits, really, and of course the run of 90s and early 2000s games.It's already the best X-Men adaptation. Hands down. It clears Logan by a bit and everything else by a lot.
It's not the best X-Men media, though. There are too many great X-Men comics, so many it's unfair to compare, and X-Men vs. Street Fighter exists.
For me, in only seven thirty-minute episodes, they've managed to hit nearly every beat of what makes X-Men so special and powerful. They just fucking get it, man. The bigger story might not be Age of Apocalypse or Days of Future Past-level, but the world, the characters, the art, the writing, it's all perfect. It's everything I love about X-Men distilled into one of the most exciting, gorgeous and politically conscious shows on television.
I just can't gush about this show enough.