Fast Five>Furious Seven>Fast Six>The Fast and The Furious (Fourth)>2 Fast 2 Furious>Fast and Furious>The Fast and The Furious: Tokyo Drift
For me I just feel that the movies have to gradually escalate in terms of warfare and over the topness because otherwise the series would just get boring. Having said that though, I am starting to worry about the future of the movies because they just seem too silly now; devices that can let you find anyone anywhere across the globe, the whole character of Deckard Shaw and him just chilling eating a meal in a warehouse one minute then having a fight of wrenches with Dom the next minute, the inclusion of Mr. Nobody and the shady government people who we know absolutely nothing about etc. I thought Fast Five was the peak; it was still about racing, pushing it to the limit etc. but it escalated how much the crew did in terms of robberies and heists. They were always pulling heists - always trying to rob trucks and their tankers in both the first and fourth one, they were always trying to make a shady deal with the feds to get off easy as that's also how the first movie started with Dom and Brian. But then the sixth one came, and brought back Letty which I just didn't like at all, killed off some good characters and the crew found their match in Owen Shaw - then they just made things worse on not writing a good story or screenplay and have grown to rely too much on things like 'Oh hell nah they gots a tank yo!' 'Oh look we did this in this film and this in this film but this right here is definitely crazy and I ain't doing it' etc. The series just feels like its becoming a lot like the Expendables where they regularly try to churn out a movie every two years, get loads of big actors involved, write a cheesy story and poor screenplay with lots of plot-holes, try to set it everywhere and anywhere and gradually separate from what the series was originally about and make it so surrealistic. That's my worry anyway.