The Texas Chainsaw Massacre: (1974)
The greatest horror film ever made (TM) - now complete and uncut and re-repackaged for, hopefully, the last time (until the Blu-ray).
Exhaustive (exhausting) rack of commentaries (everyone from director Tobe Hooper to tea-boy) and some ace featurettes (best is Gunnar 'Leatherface' Hansen conducting a tour of The House). The film itself hasn't dated a day - a pummelling jolt of primal terror.
Silent Running (1972)
Love him or hate him, but Mark Kermode was bang on the money when he said that Wall-E owes a tremendous amount to this little known flick from the early seventies.
Directed by 2001 special effects guru Douglas Trumbull and starring Bruce Dern, Silent Running is everything that Pixar’s 2008 hit sets out to be, but without the Disneyesque sentimentality that plagues the second half.
No extra features unfortunately, but a must-buy for anyone who likes their sci-fi.