Need a reason to love X-Men: Days of Future Past? You have plenty to pick from. Love it, if you want, for the way it deftly mixes the cast of the original X-Men trilogy with that of X-Men: First Class, the 2011 prequel, without spreading itself out too thin amongst a bunch of different characters. Some mutants are given appropriately meaty roles (James McAvoy's young Xavier, Jennifer Lawrence's Mystique), while others serve as just a bit more than glorified cameos. (While still more are literally nothing but a glorified cameo.) The important point is: everyone is used to serve the story as opposed to the actor.
Love it because that goes for Hugh Jackman's Wolverine as well. Wolverine is still central to the story being told and gets plenty of screen time as a result. But, for once, he serves as more of a catalyst than as the film's emotional core. It's a win/win for everybody. You get plenty of Jackman, and he's as great in the role as he always is. But the movie wisely doesn't spend time examining Logan's poor tortured soul, as so many other X-films do.
Love it for Quicksilver, who looked so dumb in those early stills, but who brings a breath of fresh mutant air to the franchise via a thrilling action sequence where he's tasked with breaking Magneto out of an underground prison located beneath the Pentagon. (I saw Days of Future Past in 3D, and while most of it proves predictably unnecessary, the extra dimension pays off when you're seeing the world in "Quicksilver time.")
Love it for the other nifty action scenes that make great use of teleportation portals, fire blasts, freeze beams, good ol' mutant hand-to-hand combat and a huge variety of well-realized super powers. For the portions of the film set in the 1970s, director Bryan Singer (back after leaving the series following X2) was wise to carry over the jaunty tone Matthew Vaughn utilized in the 1960s-set First Class. Even the bleak future sequences — where the world has been ravaged by a Sentinel vs. mutant vs. human war — are lively and not overly dour.
Singer and screenwriter Simon Kinberg also refuse to let the film get too bogged down by time-travel specifics or matching up continuity-wise with earlier films. If you've been bothered by the spotty continuity in past X-films, you're going to go nuts here. Kitty Pryde now has time-travel powers for no reason what so ever other than the film needs someone to have them! Honestly, at this point, I think the wonky continuity is kind of endearing. No longer am I opposed to wily-nily partial continuity. Retconning has been a staple of the comic-book industry for years, and to see it employed so flagrantly with these movies strangely makes the X-Men franchise feel like a more honest replication of its source material.
Speaking of retconning, love Days of Future Past for its ability to nimbly brush the series' past mistakes under the rug as it uses time-travel to partially reboot the franchise. The last 20 minutes of this film are so satisfying, you almost wish they'd just end the series now and let this stand as its feel-good swan song. Since that's not going to happen, at least the movie frees the franchise to go in pretty much any direction it wants with any cast members it wants from this point forward. Hopefully, whatever comes next is just as much fun.