Wow, having just watched them all through Apocalypse, Im going to have to change this and it looks radically different1. X2
2. X-men
3. Xmen DOFP
4. Xmen First Class
5. The Wolverine
6. Deadpool
7. X-men Apocalypse
8. X-men: The Last Stand
9. X-men Origins: Wolverine
I like that as an abbreviated running order. Off the top of my head I can't think of any inconsistencies arising from doing it that wayNot ranking per se, but I see 'em like this...
Prologue: First Class
X-Men
X2
Days of Future Past
That's a perfect trilogy (with four movies).