HE WAS THE FINEST MAN I'VE EVER KNOWN! If you've seen the blooper reel of The Avengers, you know what I'm talking about. Before Agent Phil Coulson got his own TV spin-off, The world only knew him as "that guv'ment spook guy in the background in all the Marvel movies." He was kind of funny, kind of nice, and kind of unimportant beyond his position as Agent Exposition for the real heroes. Naturally, nothing big was going to happen to him. Then Joss Whedon came along and decided people would suddenly love him retroactively if he were mercilessly slaughtered.
By adding little touches such as Tony Stark subtly mentioning that Coulson had a romantic prospect, and Coulson himself gushing about his Captain America trading cards, this background character slowly worked himself into our hearts. Then Whedon ripped our hearts out. HE SHALL BE AVENGED!
Anyone remember this horror film? It was pretty good, one of those slow burns where the hook is that the villain is a handful of creepy people wearing masks. Their motivation is never explained, when asked why they were committing such atrocities to innocent people, they respond "Because you were home." Ok, I'm on board for this, but did you know Dennis from "It's Always Sunny in Philadelphia" gets shot for no reason?
I was as surprised as you that Dennis was even an actor outside of that show, but when the main girl refuses a marriage proposal from the main guy, he calls Dennis to pick him up from the not-so-romantic vacation house. Then between then and Dennis showing up, the crazy peeps start their shtick, so everyone's on edge.
What gets me is Dennis was just being a good friend. His bro calls and asks for a pick-up, and Dennis comes through. And ultimately being a good buddy gets him killed BY THE GOOD GUY, who had gotten his hands on a shotgun and thought Dennis was one of the murderers. Lesson learned: never do any favors for any friends, or else they will murder you.