The X-Men are probably the deepest comics ever written. They're a group of societal rejects who fight to defend and preserve the basic human rights of those that would deny them their own basic human rights. They're unappreciated and even ostracized...but still they fight on.The true meaning of heroism. Incredible, really, when you think of it.
This was probably the first philosophical thought of great depth I ever encountered that wasn't explicitly tied to my Catholic upbringing, and ever since I was a little kid, it's been blazed into my brain and heart: "With great power comes great responsibility"