This one's pretty simple... best cult / horror movie ever made. period.
Being an intimate fan of many movies, books and music artists... it becomes more-and-more difficult to choose true favorites... there are so many great works of art out there, how do you choose just one?!?
When push comes to shove, or shove comes to dismemberment... I can honestly say, without a shadow of a doubt, that The Texas Chainsaw Massacre is the most well realized horror epic ever captured on film... only one other movie I've ever seen required me to ask myself... "is this real?"
That would be "Sid & Nancy"... since Gary Oldmans portrayal of Sid Vicious was so incredibly believable (and admittedly, my knowledge of the Sex Pistols story was lacking at the time)... that brand of storytelling takes real magic, to convince the viewer so deeply, they feel like they're watching something actually happening.
TCSM does just that. Director Toby Hooper built a world where those in it are disturbingly realistic... despite their insane psychological personas and extreme physical scars... you know, deep down, these people are out there in the real world somewhere... and for all you know, you're accidentally watching a really weird snuff film (because we all know those don't exist).
The Texas Chainsaw Massacre is more real than it is fake... making it wildly riveting, and truly scary.
Trivia: Did you know the opening introduction voice-over was done by John Laroquette... aka Dan Fielding, the sex-crazed prosecutor / lawyer in the TV sitcom 'Night Court'... yeah, really... how he managed to score the TCSM intro almost a decade before he made it to sitcom stardom, is quite a trip.