Ok everyone we've had numerous articles of who would win in a DC vs Marvel battle.
Let's take a different approach and look at things. In this scenario you have to setup the ultimate super-team(s). It can be composed of members from any superhero comic universe. Can have up to 10 members but you can not have duplicates but overlap is okay. So you couldn't have Superman and Shazam as example because both serve the same purpose, but Superman and Martian Manhunter would be fine if MM was your tactician. The team has to be able to work together, so keep in mind how they've been shown in their stories. Would hero A be able to work with hero B or villain C in this team up? And yes the teams can be composed of hero or villain or combinations of both.
Scenario 1: Alien invasion that threatens to destroy all life on Earth. The aliens are shape-shifters and can mimic anyone they come in contact with.
Scenario 2: Darkseid has acquired the Phoenix force and has joined with an Infinity Gauntlet wielding Thanos to locate and obtain the anti-life equation giving Darkseid his ultimate reward and bringing Thanos closer to his love Death.