For as long as I can recall thinking about such things, I've been a big proponent of free will. The notion that I, and I alone, control my actions and that any consequences of those actions are mine to bear. As near as I can determine, it was this firm belief in free will that has guided/directed my thinking towards religion, politics, entertainment, and just about everything else. After college, I began mentally exploring that notion further and have come to think of myself as something of an existentialist. While there are any number of variations of existentialist philosophy, the basic premise takes free will a step further by stating that the meaning(s) of our very existence is entirely up to the individual.
I seem to recall seeing/reading an article some years back discussing Krazy Kat in an existentialist (instead of the more typical surrealist) light, but I can't seem to find that at the moment. This particular strip (from December 25, 1919) speaks directly to the two characters' differing approaches to what is or isn't their respective realities. But it's certainly not the only comic that brings up the notion of existentialism.
Time travel is a notion that comes up frequently in comics -- as well as other media, but I'm talking comics here. The two primary notions that tend to come up in some fashion are A) that anything a character does in his/her past is in fact already a part of his/her part and s/he was destined to carry out those actions, and B) history is mutable and subject to change -- a media-centric shortcut to explaining that position is Back to the Future. (There are variations on these ideas, obviously, with alternate timelines and such, but they still tend to generally follow one of those two premises.) It should be needless to say that I tend to favor stories that dismiss the notion of destiny or inevitability. Because of my fairly strong feelings on the matter, I tend to approach stories involving time travel with some trepidation, especially with properties that haven't previously taken a definitive stance on the issue of time travel. Both DC and marvel have wavered back and forth on the issue repeatedly, seemingly dependent on the whims of the writer and/or editor of any particular story.
That said, I can still appreciate a time travel story that holds to the notion of determinism, if it's done well. Steve Englehart, for example, did a fine job in West Coast Avengers #17-24. Technically, it holds together extremely well, keeping multiple storylines/timelines straight and still tying into established continuity on any number of points. I don't agree with the basic premise, but I have to admire the skill with which the story was executed. By contrast, Roberto Aguirre-Sacasa's Knights 4 #15-17 is fraught with plot holes stemming precisely from the time travel aspects of the story, and I disliked that story despite his holding up the notion of free will and some excellent artwork by Jim Muniz.
But that's only an obvious way to see existentialism in comics. Another issue that stands out for me is one that was never published: Captain America #14 by Mark Waid and Andy Kubert. The issue, as written by Waid, recounts a history of the Red Skull -- as told by the Red Skull himself. (Waid's original script is online here courtesy of the Star-Spangled Site. Editor Bob Harras re-wrote much of the script before it was published, putting Red Skull in a more typical -- and safe -- role as the bad guy.) The original narrative is insightful because it is that of a character who believes in what he himself is doing, regardless of the fact that most people would consider those actions "evil." He doesn't consider his actions anything less than justified because of his own goals and that Captain America is an obstacle to them. Although the Skull's thoughts themselves don't necessarily relay an existentialist message, the very notion that his perception of events differs from the title's usual protagonist speaks to the idea that each man is creating a reality based on his own thoughts and opinions.
I think that one of the (subconscious) reasons I took to the Fantastic Four early was that it readily exposed the difference in approaches with Mr. Fantastic and Dr. Doom. Doom's very character is based in large part on revenge against Reed Richards for a perceived slight back in college. Reed, by contrast, always takes the opinion that the error was Doom's himself and he has never acknowledged that fact -- Doom is, in effect, absolving himself of any responsibility for his situation. The difference in characters are further highlighted by Reed repeatedly taking responsibility for the accident that caused his friends' conditions -- most notably that of his best friend, Ben Grimm. And similarly, Ben does NOT blame Reed for his own state (at least, he didn't by the time I started reading the book; the first dozen or so issues, Ben very clearly and adamantly did blame Reed). Ben has accepted that he elected to take on the risk of piloting that fateful space flight, fully knowing that there was a great amount of risk. The Fantastic Four (the good guys) believe they created themselves, while Dr. Doom (the bad guy) believes he was created by others.
Now whether or not you agree with me on how much responsibility we have for our own actions is immaterial here. But I think it's an especially intriguing notion to examine how some of my core belief system ties in to what I like to read. As I write this, I am the product of every decision I've ever made, and so I'm left to wonder who would I be if I had made different choices? Would I have taken to the Fantastic Four -- or, indeed, comics in general -- if I was more determinist in nature? Would I be reacting differently to events in my personal life the way I am? Would I even need to be dealing with the same things with a different outlook? Certainly interesting, if ultimately unanswerable, questions.
But let me put the question to you: how do your personal philosophies impact your choice of comics reading? I don't expect answers here, mind you -- I can only address the issue now because of the insane amount of navel-gazing I've been doing lately -- but it might be something worth examining for your own personal edification.
Self-actualization through comic books! Who knew?