You’re walking down the sidewalk, listening to your earbuds, contemplating getting a slice of pizza for lunch, when you bump into an old friend that you haven’t seen in years. Ya’ll start up a conversation, getting caught up, and he notices you are wearing your favorite Batman t-shirt. He makes a small snide comment about how he just doesn’t get all this Superhero stuff, and why everyone is so hung up on it. 
Your palms start to sweat, the sky has suddenly grown darker, with a faint rolling thunder in the background. It feels like the world has literally come to a stop. Your brain is working overtime to decide which pathway to go down, in response to this statement that was just made. Do I get agitated, and tell them that they just don’t get it? Or do you take this as an opportunity to help your friend see the Truth, the Light, the Inspiring world of comics? 
You decide to let cooler heads prevail, and you opt to go for latter, and see if you can convert them to the beautiful creativity of comics.
So here is the question… Out of All the DC Characters, Stories, Adventures, etc… What is the Perfect, One Issue Comic Book That You Ask Your Friend To Read, To Try To Change Their Mind?
This is a tough one. There are so many great answers, but I have to say Batman: White Knight #1. That whole series is a perfect example of the potential of comic books to tell fantastic stories with phenomenal artwork. It’s the perfect start to a perfect series that I’m confident could get anyone in interested in comics.
Back in 1989 after I was six months into reading and collecting DC comics the cashier at the comics store that I used to shop at pulled an issue down off of the display wall behind the register for me that absolutely blew. my. mind.
After reading the first issue of this landmark series I was absolutely mesmerized and immediately started saving my sheckles so that I could amass the other eleven issues and find out how this incredibly compelling story ended. I would most def without reservation recommend Watchmen to anyone whose on the outside of the comics world looking in.
These are some great ones. !!
Reason I made this question, was I’ve been in this exact situation, (I’m sure most of us have). So I just wanted to hear from ya’ll. If ya’ll had been in similar situations, and what you would recommend as the definitive comic book to try to win over your skeptical friends.
Red Hood and The Outlaws issue #1.
Let the introduction and Dexter Soy’s beautiful art persuade them.
(Also Jason’s thighs work too 
)
EDIT I just want to clarify, NOT MY COPY, I don’t trust people with lending stuff, they will never come back and that is not a fate I want for my precious… comic…
I’d give them the issue that drew me into the promise of the DC Universe as a whole entity: 52 #1. Take away Superman, Batman, and Wonder Woman, and what does the universe has to offer? To start, a good Question.
… not sure. Maybe DC rebirth #1. A good intro to the current universe of DC and if any interest them they could continue the one they like. If not probably white knight as mentioned here. Batman a common gateway for most people while having tastes of and out of continuity story with new and classic bat stuff. Also short and sweet so they don’t seem overwhelmed.
^ If I had to pick one issue. But in those situations, I don’t try. If they’re not close friends, I shrug and ignore it. If they’re close friends, I can be more free with F bombs 
Red hood and the outlaws (Rebirth): issue 1
Superman #75 (1993). The Death of Superman! One of the best issues ever!!!
Sandman Volume 2 Issue 18, “A Dream of a Thousand Cats”
Shhh, don’t give out my secret identity, the police will be after me
Good thing it’s blurred, I suppose
It succinctly encapsulates what came before in the story while concluding on a heart-wrenching note. Once you finish it and process the emotional impact, you have to remind yourself you were reading about a fictional character as you wipe away a tear and say “Superman cannot die. He will win, somehow.”
At least, that was my experience when I bought it at the age of 9. 
For me when Superman turn into a blue energy hero, I was always looking forward to see what would happen next!
Wait, how does Neil Gaiman know what I dream about?
I wouldn’t I would immediately just slap them