I had the chance to read the most recent DC/Marvel crossover recently. By "recent" I mean "2003-4," since there have been other crossovers, such as the X-Men/Teen Titans crossover and the Amalgam Universe titles. If you haven't read this series, or the collected edition that I found in my public library, it's worth a look, especially if you're running a superhero game.
For one thing, it's Busiek and Perez, two top names in the industry. I loved the Busiek/Perez run on the Avengers at the time, and frankly feel like it was the last time the team really felt like the Avengers to me, although the "Heroic Age" came awfully close.
The plot is pretty straightforward. Krona, an exiled Oan, comes to the Marvel Universe looking for the truth of creation, in the process destroying several alternative universes, including the "Earth 2" of the Crime Syndicate of America. When he gets to the Marvel Universe, the Grandmaster challenges him to a game: the greatest hero teams of the two universes will compete to find twelve uber-powerful objects. Krona agrees, but with one condition: he gets the Grandmaster's team, the Avengers, and the Grandmaster gets the Justice League.
Both teams then end up hopping back and forth between the two dimensions, first opposing one another and then eventually teaming up. There are lots of little bits to make comic book fans happy. Dream contests occur (Superman versus Thor, Captain America versus Batman). Jokes are made about overly similar characters like Hawkeye and Green Arrow. Hercules mentions his dalliance with Hippolyta to Wonder Woman. And Batman takes a small side-trip to kick the Punisher's backside. Off-panel. Because the Punisher is a jerk.
But the part that makes this really interesting is the way they explore the real differences between the two core ethoi of the comic book universes. It can best be summed up in one exchange, in which Batman meets the Thing briefly.
[Batman]: "He has a...rough edged charm."
[Captain America]: "Was that a knock? Ben Grimm may not be sleek and elegant, like the heroes of here, Mister. But he's one of the finest men I know--and he gets the job done."DC heroes? They are wonderfully iconic with their capes and symbols. Marvel heroes have rough, human edges. When the two teams first visit each other's worlds, the League is aghast at a world where there is a Latveria, a Genosha, and even the Hulk. The Avengers, especially Captain America, are suspicious of the adulation of the populace towards their heroes and suggest they are crypto-fascists.
That contrast is, among many other reasons, why I suspect Marvel characters look better in movies while DC characters have done so well in cartoon animation. Broad shoulders, spandex, and capes work in cartoons in way they just can't be carried off in real life. (Plus, the animated series respected the decades-long traditions of the characters and were marketed to comic book fans, while the DC movies always tried to re-invent the characters and target people unfamiliar with the legends. But I digress...)
When it comes to creating your own superhero RPG campaign, I think there is some question about what kind of heroes the PC's will be: iconic or marginal? And, what if those roles were changed?