I feel like Die Hard doesn't reach epic status.

Great movie, but I don't think it has the depth of story that an epic needs.

I think it shows the difference between an epic and a blockbuster. Die Hard was definitely a blockbuster.

When I think of an epic, I'm thinking of something that goes beyond just a great movie: Gone With the Wind, Dr. Zhivago, How the West Was Won, etc. Something that makes you feel like you lived a life while watching it.