Top Vote: Nathan's Nicely; sgcat; montrealxo; katysus
Powers/abilities: Genius-level intellect, Peak human physical and mental conditioning, Master martial artist and hand-to-hand combatant, Master detective, Utilizes high-tech equipment and weapons
Another iconic superhero, he coined the "sidekick" term with his actual sidekick Robin, has an iconic archnemsis, The Joker, and various known allies and enemies.
Powers/Abilities: Enhanced physical condition, Enhanced mental faculties, Master martial artist and hand-to-hand combatant, Mastery of various weapons, Expert marksman, Master tactician, strategist and field commander, Wields vibranium-steel alloy shield
Another of the "original" superheroes. Steve Rogers was scientifically enhanced to be used as an unstoppable force during WW2 but was trapped in ice and stayed in a suspended state until his discovery years later. He is usually portrayed as the leader of the Avengers, and dies at the end of the Civil War comic series.
Powers/Abilities: Vast telekinetic and telepathic abilities. As Phoenix, Jean possesses vast cosmic abilities which make her nearly unstoppable.
While on a mission in space, Jean Grey is exposed to large amounts of cosmic radiation and is taken over by the Phoenix Force, turning her into Dark Phoenix which gives her immense power where she consumes a star, destroying an entire planetary system in the process. Overwhelmed with all this power, Jean Grey commits suicide in order to save the universe.