No idea why I was thinking about this but here we are...
Growing up, movie theme songs (Star Wars, Indiana Jones, Mission: Impossible, Top Gun, Rocky, etc) were a well-known and integrated part of the films themselves. I can hum them off the top of my head and all of them seemed (or still seem) amazing to me. They are almost as recognizable as the movie poster or movie title themselves.
These days, I feel that's not the case as much. Sure, some blockbusters still have theme songs (The Avengers films come to mind), but I cannot think of anymore as I write this (I don't even know if there's a consistent track for the DC comics movies). The same could be said for TV series as well. Instead of long songs and introductions every episode, it's usually a short jingle of sorts and a title screen and that's it.
All that being said, what is your all time favorite movie or TV theme song. You can only name one.
For me it has to be Star Wars. There's just a certain emotional response I have to it that I don't get with others.