Edge of Tomorrow (2014) , good action sci-fi.
I personally think time travel is a fantasy. The past is gone and the future hasn't happened yet, only the present exists.
Time can slow down for people traveling close to the speed of light, and that's the only way the universe allows anyone to travel between stars, in their life time, but the rest of the universe has aged considerably, so it's not very efficient.
The only other possible way may be worm holes, but it will take thousands if not millions of years before we have the knowledge to create them, if it's even possible.