Being almost 60, there have been too many to pick one, so here's a few.
M*A*S*H - Col Blake (probably my number 1)
Top Gun - Goose
The Force Awakens - Han Solo
Glen - Walking Dead
Agent Todd - NCIS
IronMan - Avengers End Game
Boromir - The Lord of the Rings: The Fellowship of the Ring
Most recently though, Clay Spenser in Seal Team. He was the next Bravo 1 and they killed him off due to his other show. Absolutely crushed!
That's a good starting point. Can't wait to see what others think.