When comic books first started out, the genres it tackled were a lot more diverse. Everything from comedy, crime, sci-fi, horror, romance, and fantasy were equally covered, usually through short story anthologies. However, when the 70s rolled along, spandex-clad superheroes started becoming popular and it wasn't long before the industry became completely dependent on characters that wore brightly colored spandex.
Don't get me wrong, superhero titles kept the industry afloat for several decades (and it seems to be doing the same for movies right now), but it has a very specific downside: it created a specific breed of people who dismiss comic books as childish pap catering to kids that take people who wore underwear on top of pants seriously.
Of course, there are gems like the Watchmen, Sandman, Hellblazer, Preacher, Transmetropolitan, and many of the horror anthologies that were still ongoing at that point in time, but they tend to be the exceptions rather than the rule. If you started reading comic books because of the above titles and you're looking for more, here are a few gems you can check out. You might enjoy them even if you hate spandex-clad superheroes:
The Boys features a group of black ops agents funded by the CIA, who are tasked with keeping superheroes in check. Did I forget to mention that Ennis hates superheroes? Because this title portrays superheroes as complete berks who abuse their powers and status to satisfy their materialistic tendencies and base carnal needs. You can literally count the real good guys using only the fingers on your right hand.
Not that The Boys themselves are shining examples of morality. The group has a couple of sociopaths in their roster, and at least one serial killer. But they are the last line of defense against multinational corporations who wish to use superheroes to mollify and crush people into obedience, and superheroes on a permanent powertrip.
A word of warning about The Boys - if you're not familiar with Garth Ennis' works, you need to be ready for offensive language and subject matter, including crude sexual themes and lots and lots of over the top violence that could have been left out without losing any of the story.
Written by Mike Carey and spun off from Neil Gaiman's Sandman series, Lucifer focuses on the Morningstar himself, right after he grew tired of his role as the Adversary.
Lucifer already abandoned hell and retired to a quiet life as pianist in one of the best nightclubs in L.A. in the pages of Sandman, this spin-off follows him as he grows tired of that life as well.
Don't let the title fool you into thinking that Carey is portraying Lucifer as a tragic, misunderstood hero that needs to be admired. It's still the same angel who rebelled against his creator for selfish reasons. He's the same fallen angel feared by angels, demons, and gods alike because he is ruthless, manipulative, and extremely cunning; that, and the fact that he's one of the most powerful beings in the cosmos save for his creator.
One of the key takeaways from Lucifer is that the fallen angel was not the horned, cloven hoof devil that stands on people's shoulders and tries to get them to do evil things. In fact, if there ever was a lesson on the comic, it's that people have free will and must be responsible for the choices they make instead of using devils, gods, and predestination as an excuse for doing what they really wanted in the first place. Lucifer himself was constantly trying to escape predestination and his role as the devil, leading him to all sorts of places and conflicts with godlike beings from different pantheons.
This doesn't need to be a spoiler because the series is told entirely in flashback, but Supergod's main gist is that mankind's constant refusal to accept the limits of what they can do is what will eventually lead to their own demise. The series starts with the planet already scorched and flooded with waste, as a result of several "gods" going haywire or merely doing what they were meant to do (create an A.I. that's programmed to cleanse an entire nation, then give him powers on a molecular level? Yes, that would be a good idea Mr. Scientist). It can also serve as a What If scenario regarding the arms race, where different governments started building planet-busting weapons of mass destruction as a deterrent against perceived threats from other countries.
Technically, The Sentry is a tights & spandex title, with the character himself now part of Marvel's mainstream continuity (and a member of Avengers to boot), but the character originally started in a miniseries that works as a stand alone title focusing on one of the most powerful superheroes in the planet, who is also suffering from schizophrenia and drug addiction.
The miniseries follows Bob Reynolds, a middle-aged, slightly overweight husband who wakes up one day and remembers that he's The Sentry, one of the most popular superheroes in the planet, with the power of "a million exploding suns" and an intellect that can easily rival Reed Richards' and Tony Starks'. Despite being Reed Richards' best friend, the person who taught Angel how to fly, and the person who first landed Peter Parker his job by agreeing to a photograph, nobody except for the Hulk remembers The Sentry.
What's worse, the reason why Reynolds started remembering his own past is that his archenemy and one of the most powerful villains in the planet, The Void, is about to return. The entire 5 issue run is full of twists and turns wrapped inside a solid story, which includes a tightly-wound narrative that explains why Marvel's equivalent of Superman is practically forgotten, what he was doing all those years he was away, and why he had to go away in the first place.
The beauty of Planetary is that it can tackle some of the sillier aspects of pop fiction and try to make them logical and reasonable, at least within the constraints provided by the medium and what little we understand of physics (for instance, what happened in Monster Island and why it's full of giant monsers like Godzilla and Mothra, or what exactly are ghosts and why is one of them appearing in a street crossing in Hong Kong, or even the technology behind Don Blake's wooden cane and why it can transform into the hammer of Thor, Mjolnir.) Planetary also has a very practical and fairly understandable application of time travel and bullet time slow motion, instead of treating them as mere plot devices that can advance a story further when natural progression and logic have already failed.
Irredeemable is a great character study on Superman. All these years, people dismiss Superman as a boring, one-sided character who is invincible and uncorruptible. They tend to write the Kryptonian off as a poor choice of character because he can't be defeated and has no moral quandaries because of his perpetually positive outlook. Irredeemable shows that there's more to Superman than just being a very powerful role model.
For instance, the Plutonian shows that Superman's best traits are a strong character and the conviction to carry the proverbial weight of the world without expecting anything in return. In Irredeemable, the Plutonian is a flawed, very human character who carries on the task of watching over an entire planet while still expecting at least a little bit of appreciation and respect that so few people are willing to give. The Plutonian is what happens when Superman snaps from all of those years of toil and labor and unappreciated sacrifice - when simply reaching out to people who try to criticize him and 5 minutes of much needed reflection time can result in the deaths of thousands.
Additionally, Irredeemable also addresses some of the inconsistencies in Superman's power, and tries its level best to ground some of his amazing feats in logic. For instance, it addresses why Superman is able to lift an entire mountain or a huge airplane off the ground without the whole thing crumbling around him, or why his skin can't be pierced or burned.
Other Modern Comic Books
We've gone past the days of cosmic beings visiting earth for pure amusement, holding tournaments between superheroes, and we've also gone past the days of running really fast around a fire just to get time to reverse or fire to get cold. Superheroics is basically a genre, and no single genre can be bad on its own merits. Comic book writers these days have started writing stories that aren't meant to cater to the imagination and limited understanding of children. You can give them a chance, and you may find a title to like. Of course, a lot of them are still burdened by decades of conflicting continuities and tangled webs of editorial mandates, but you can usually cherry pick titles in order to get ones that are easy to get into simply by doing research. That's what the Internet is for, right?