[Each week, depending on what's in theaters, what's in the news or what's on his mind, film critic James Rocchi brings you the Retro Rental, an older film on disco or download that connects with the here-and-now ...]

And that's the problem with time travel, or at least part of the fun, which is that where you enter into the story may not be where the people in the story are coming into and out, like we discussed earlier. In 'Looper,' time travel works the same as a one-way bus ride to Muncie, if Muncie were 30 years before in the time-and-space continuum and the bus broke every rule of physics as we know it. In 'Primer,' the time machine works in a similar fashion -- never putting you forward, exactly, but rather putting you back so that you can move forward from that back and do everything over again, but different, and since only you have any knowledge of what really happened before, why not change it?

'Primer,' of course, came out of nowhere to win the Grand Jury prize at Sundance in 2004, and the look on writer-director Shane Carruth's face when he won the award was priceless. Made for about $6,000 -- or, in other words, a sum of money that wouldn't buy you a decent used car -- and shot on film, it told the story of two kinda-sorta co-workers and friends -- and, as the film progresses, kinda-sorta friends and co-workers -- played by Carruth and David Sullivan, who while working on a part-time startup in their garage, get some funky experimental results as part of testing new materials for the widget they're building. Impossible results. Or results that would only be possible if time were somehow reversing in the middle of their experiment, which it seems to be doing. And soon, at great risk to their health and sanity, Carruth and Sullivan figure out how to time travel with their device, which enables them to, say, live 18 hours of Thursday, spend 18 hours in their device and come out 18 hours at the beginning of Thursday again...

Rian Johnson's 'Looper' opens in theaters this week, with future-crook Joseph Gordon-Levitt tasked with killing an even further-future version of himself, Bruce Willis, as part of both his and Willis' retirement plan... (Ominous, that; sure, you get a gold watch... but you have to shoot yourself and pull it off your dead body.) To make 'Looper' -- or, rather, to make 'Looper' better -- Johnson turned to Carruth, a friend and time travel enthusiast, to tell him where it was his rules for chrono-bending were being kept and where Johnson was cheating, and that helped Johnson, as he explained, immeasurably. Calling Carruth a time travel "Enthusiast," really, is kind of like calling Michael Phelps 'not afraid of water,' as Carruth wrote, directed, edited, composed for and starred in 'Primer,' one of the best time travel movies ever made. I've known people to go semi-mad trying to unravel the movie's twists in chronology with diagrams, web charts, Power Point diagrams... and they never quite get it, but they never stop trying to figure it out, either...

Recently, a group of critics at Indiewire's Criticwire named their favorite time travel movies, and while I wasn't surprised to see such warm-and-well-loved bits of comfort food on the menu as 'Bill and Ted' and 'Back to the Future,' and also found a few discerning tastemakers picking 'La Jetee' -- not it's Terry Gilliam remake, '12 Monkeys,' thank you very much -- I had a different set of reasons for my pick. I know that 'Back to the Future' or 'Bill and Ted' have a lot of fun confusing their characters, but we in the audience get to sit back and watch things unfold so that we aren't so much travelling with them as we are afforded a slightly higher-up seat on the same bus -- watching them, laughing at them, but always kinda-sorta above the action and them. And to me, that's kind of not the point of time travel; if you're not going to splash people around in paradox and causality and chaos and confusion, and accidentally shooting your own grandad when he's a 5-year-old, you're not in on all of the fun -- and fearsomeness -- of the experience. Which is, by way of introduction, where my pick for the title of best time travel movie ever, 'Primer,' comes in.

'Primer' is available on DVD.

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