X-Men: Days of Future Past
The original X-Men movie trilogy fell a bit flat by its third installment, but the line was rejuvenated by the X-Men: First Class reboot that took us back into the past with the original members of the team. X-Men: Days of Future Past did something special by blending the two. It took the great cast from the original three movies, set them as the future selves of people from the reboot, then had Hugh Jackman doing some time-traveling to fix the timeline. It is really handled well.