Okay, so my inner and very outer nerd is a bit disgruntled with the excess of DBZ v Superhero "Who would win?" situations. Why? Bc it's a non-issue. In the sense that there is a clear correct answer. And nerd Sam will tell you why.
First off, this is the main picture in question:
It shows Vegeta and Goku against all of Marvel. Now, who would win? That's easy. Goku and Vegeta.
Reason 1:
Goku and Vegeta are two alien species who, in the Dragon Ball Z universe, are driven by one another to become the strongest fighter in the universe. They have more determination than any single Marvel OR DC character. How many episodes of DBZ were spent watching them train? Probably like 25%. Ever see any of the superheroes train? NOPE. There is no way their respective skills would be fine tuned enough to handle Vegeta and Goku.
Reason 2:
I am going to argue this reason using only the Saiyan Saga. For people who lacked a childhood, that's the first season of Dragon Ball Z. In this saga, the weakest Z Fighters the earth has to offer fought the Saiyamen. The absolute weakest of all fights throughout the entire series aside from maybe Goku & Piccolo v Raditz. During this fight, they are moving so fast, that the human eye can't even see them! They have to sense their ki. And again, the weakest instance in the show. No one in Marvel can move that fast. So, insert the 2 strongest fighters in this saga. Goku and Vegeta. They're faster than anyone in the comic books.
Reason 3:
In continuation, we see Goku and Vegeta beating the absolute piss out of each other. Throwing each other into mountains and Vegeta even turns into a giant monkey and breaks Goku's entire body. Whole body. And lives. Who is going to take one of those hits? There are 5 possible answers...
Reason 4:
If you side on the superhero's side, you have 5 possibilities for any type of hope. The Hulk, Wolverine, Superman, Wonderwoman, and Thor. Thor is a god. Superman and WW are basically gods. Hulk and Wolverine are known for being indestructible. Superman is the only one who can move fast enough to put up any sort of fight....the fast as a bullet thing which is still too slow. Now, my final argument is this: Vegeta at his weakest in the series, has the power to destroy the entire planet in one swift attack. None of these 5 could fathom that. Now, let's have Goku and Vegeta fuse into Gogeta. Now, go SSJ4.
I'm done. *Drops mic. Flips bird. Exit stage left.*