Mine is probably Blast From The Past a silly romantic comedy that was on TBS every Sunday for years and the tv would be on so it would be running in the background for whatever I was doing. Brendan Fraser, Alicia Silverstone, Christopher Walken, Sissy Spacek, Dave Foley, Joey Slotnick. Nathan Fillion. etc. A nicely structured entertaining movie but a 5/10 for me.
Of the movies I have intentionally watched, I would think that my most watched would either be Citizen Kane or Run Lola Run.
Although I have may have seen La Jetée more than that but I am not sure that counts as it is a short.