A recent post on TopTenz offered the Top 10 time travel movies. With all due respect it's not clear that "time travel" was an important concept in this list. For example, in the Terminator movies there is a single time travel event at the very beginning of the movie and then nothing more. While the characters attempt to change the future there is no evidence they succeed. There is no foreknowledge or time loop or time machine. I would not call this a time travel movie because time travel is not possible for anyone after the beginning of the movie. As for Star Trek movies, they just aren't serious enough. The time machine is their spaceship, and apparently they can travel in time whenever they like.
I think a time travel movie should have
1 A time machine or time travel mechanism right there in full view
2 Multiple instances of time travel
3 A time loop or paradox
4 Tension associated with the time-travel, a chance of temporal disaster.
So here is my own list of the Top 10 Time Travel Movies (free of Amazon links)
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1 Primer
2 12 Monkeys
3 Back to the Future I, II, and III
4 Timecop
5 The Time Machine (new and old versions)
6 Time Bandits
7 Bill and Ted's Excellent Adventure
8 Frequency
9 Timeline
10 Butterfly Effect I ( II was not good enough for this list)
Unfortunately there is a dramatic difference in quality towards the end of the list. I think Hollywood should look at this an opportunity.