For me, there was rivalry with Exeter in the 70s. In the midst of general rampant hooliganism I travelled by train to Exeter c 1977 aged about 13 with a few mates thinking I was a big man, but actually was shocked a bit. The green army ran wild in the city centre and at the ground, causing havoc wherever they could and on the way back the train was completely vandalised and the emergency cord pulled a dozen times. It took hours to get back.
Then by about 1979/80 and the two tone / skinhead period it got a lot more tense away to Exeter ( no longer a simple pushover they were up for fighting back ).
I also remember going with a load of Argyle fans in the early 80's in the popular side at Torquay to cheer on Torquay against Exeter, with a number of Argyle fans looking to go further of course.
This could even have been the day in 1977 where you will see footage of an Exeter fan being beaten badly and a pitch invasion etc.
Can anyone identify the Argyle player who classily trips up the pitch invader ? Is it Alan Rogers ?
Exeter city V Torquay United at St James Park in the 70s
www.youtube.com