TMR

Stands for "The maze runner", a well known book and film, written by James Dasher.

Person 1: "TMR is my favourite book series ever"
Person 2: "yeah, same!"

TST

TST stands for 'the scorch trials' which is the second book and film in the maze runner series written by James Dasher.

Person 1:" Have you seen TST yet?"
Person 2:"No but I really want to!"