Superman/Batman is a current DC title that chronicles the adventures of Superman and Batman. And they've had a few. See the ten nuttiest storylines current comics have to offer.
Superman/Batman is one of the gems of contemporary comics. The title makes it look like the flimsiest possible excuse to put DC's two most lucrative characters together under a name that's either blissfully unaware of the conventions of fanfiction or actively pandering to them. That doesn't matter. If anyone thinks that the balls-to-the-wall nuttery of silver age comics is gone, they need to wade around in this series for a little while. The books have, hands down, the most creative stories being published today. What's more, they mostly have little-to-nothing to do with current continuity. They're just whatever insane idea some lucky writer pitched to an editor. This makes for a lot of crazy stories to choose from, but here are the top ten.
10. Superman and Batman murder everyone they know
In what I consider the best story about Superman or Batman ever, Bruce Wayne and Clark Kent are taken away from their parents and raised to be dictators by evil aliens from the future. As part of their dictatorial rule, they're shown killing off their regular-continuity allies left, right, and center. They start out the book by vaporizing Green Arrow, kill off Deadman and Zatanna, and end up with Wonder Woman. Although that panel of Superman killing Wonder Woman looks pretty harsh, it's understandable given that she just killed Batman. Which brings us to the next point.
9. Superman and Batman die about a thousand times
Not only does Wonder Woman kill Batman, but everyone else does too. There's a series of scenes in which both characters are hunted down and killed in various ways through various universes again, and again, and again. There's no word on how or why they survive these deaths. That part of the story is pretty much just them getting torn apart by gorillas or murdered by urban cowboys until it's time for the plot to resume.
8. Superman and Batman share a bed
The first Superman/Batman Annual told the story of the time that Superman and Batman first learned each other's secret identities. It starts, like all great affairs to remember, on a luxurious cruise ship. Clark Kent has been sent to cover the launch of the ship and review is accomodations. Bruce Wayne was there to establish himself as a stupid billionaire playboy. They somehow got booked into the same room and - voila. You have probably seen this image before. It made about seventeen laps around the internet when it was first released.
7. Superman and Batman spend an entire evening listening to two kids speculate on who would win in a fight
That's pretty much it. A couple of kids argue for an entire issue about who would win in a fight, and it ends with the heroes standing there, having been listening the entire time. The above panel is the kids trying to figure out what Superman and Batman would fight about. It ends with them deciding that Superman and Batman would never fight because they're beeeeeeest frieeeeeeeends.
6. Batman erases his own existence
The above panel is not from Superman/Batman. It's yet another panel in which superheroes fight about whether or not it's okay to kill. Batman is reiterating his position that it's never okay to kill. Since Superman is standing next to him, it's awfully nice of him not to point out that Batman has killed. In of the Superman/Batman arcs, they're brought to the time and place in which Batman's parents were murdered. Batman doesn't just disarm and kill the mugger, he does it so fast that not even Superman can stop him. Since the murder of his parents is the only reason that Batman is around in the first place, he then blinks out of existence and Superman has to go find Bruce Wayne, Actual Billionaire Playboy and get him to be Batman.
5. Superman and Batman get put into women's bodies.
Not only women's bodies, but the bodies of their allies, Power Girl and the Huntress. In case you're wondering, yes, that was Batman in the Huntress' body checking out Superman in Power Girl's body's cleavage. That actually happened.
4. Batman builds himself a boy toy
I understand if the only thing you could look at in this picture is the disturbing man wearing only a cape and body paint. I ask you, though, to look to the bottom right hand corner. That is The Toy Wonder. It's the future. Batman has the option to build himself a sidekick. He could make something huge, strong, super-smart, and emotionally mature. Instead he chooses to build himself something with the size and emotional maturity of a twelve-year-old child.
3. Superman gets stoned
One story has Batman and Superman trying to hunt down and eliminate all the kryptonite in the world. They find several new types of kryptonite while they're searching. One type is black kryptonite. It knocks Superman out, and when he wakes up he's . . . well . . . extremely interested in procuring munchies. He also almost dashes right into the sun to try to get more of the black kryptonite before Batman destroys it. So don't do drugs, kids, or you'll run into the sun. Or something.
2. An entire chibi Justice League shows up
These guys are first seen when Superman is stoned. When he looks at the Justice League members around him, he sees them as their chibi selves. (When the comic isn't looking through his eyes they look normal.) The chibis got such a big response that not only did the series base a whole storyline on a chibi Justice League, but they added a chibi Injustice League and finished up the storyline in the next Annual.
1. Batman is forced to have sex for justice
Look, there is a lot of crazy in this series, but nothing tops one particular storyline. Superman is kidnapped and taken to Apokolips, where he is brainwashed into being a killing machine. He's also soon-to-be killed himself, and Batman is the only one who can save him. After Batman is also nearly killed, he's rescued by Bekka. She's the wife of Orion of the New Gods. Orion is missing. Bekka is alone. And she's a love goddess. Her power is involuntarily making everyone capable of love fall for her, and emotionally closed-off, tormented people love her most of all. You know where this is going. Batman spends the next few pages being stripped down to have his wounds healed, stripping her down when she gets hypothermia, and even being forced - forced! - to hold her really close because they're surrounded by enemies and she has invisibility shields that only work on two people if they're pretty much attached at the hip.
At last he can't take the distraction anymore. He tells her he has to save his friend. He asks her what can nullify her powers and make it so he can give his whole focus to saving Superman. She says the only thing that stops the desire is consummation. He still says no. It takes a couple more mishaps for them to at last fall into each other's arms - and then a volcano erupts. Literally. They're distracted, and at the last moment Batman's virtue is saved. At the end of the adventure, Bekka's husband comes back, gives Batman the stink-eye, and rides off with her into the sunset.
Oh, but there's so much more. In that same issue, Superman has an out-of-body experience and hallucinates Starro bringing him a muffin basket. In another issue, Batman and Superman meet Batwoman, Superwoman, and Power Boy. In another issue Batman's version of the Batwing is a dragon. In another issue Batman and Superman crash the set of a Superman/Batman movie. And in yet another issue Batman and Superman pimp out Powergirl to a twelve-year-old. This series truly cannot be beat.