At the beginning of the "Civil War" series by Marvel, Iron Man in fact documents that the Hulk is exiled to deep space. Note also that in the same series, Spider-Man is called "one of the most powerful metahumans " in the world. When all his abilities are taken into consideration, he is a legitimate phenomenon.
Each team has its own strengths and weaknesses, and the beauty of the team concepts was that they covered nicely for one another. Many are the issues that pitted one or more members of a team against another, and occasionally it spread. Hulk vs Thor was popular, for example. The two can pound on each other all day.
As to Superman? Remember that Batman himself maintained a Kryptonite bullet for the day that the big S decided he was better than the normals on Earth. Batman, in fact, kept a lethal intervention available for all the Justice League members, simply because he didn't believe anyone could maintain the level of integrity without giving in to power urges.
Back to the OP: With relatively current lineups, I'll take the X-Men.
