Marvel has a full arsenal of heroes! My top 3 though are:
Spider-man Peter Parker literally embodies hope. He is the outcasts hero by far teaching the vital lesson that through our gifts we have a responsibility to embrace them at any costs in an effort to change the world and save those who have yet to acknowledge theres. Every time i take a stage to this day after 16 years i picture myself as spiderman and in the normal days away from the lights its a peter parker quiet life for me. What makes him so much vital as hero is that peters powers come secondary to the gifts of his humanity which make him the hero he is. Intelligence with the perks of spider like characteristics is how he thwarts any and all enemies. Humor is how he deals with times of discomfort or nervousness. Etc. etc. He literally made being a nerdy kid with glasses cool!
Penance Formerly known as Speedball i find Robbie Baldwin's transformation into a man, and Penance to be one of the best fruits of the Civil War arc. Wearing a suit with 612 internal spikes to trigger pain and unlock his guilt transformed kinetic powers; Speedball went from Comedic little boy to Dark and twisted dark hero Penance being seen as the main cause of the events that are known as the Marvel Civil War. He is the inly character i have known in the mcomicu to literally have the weight of pain and guilt on his heart physical alter the parameters of his abilities so much so that his entire character justifiably changes showing a true display of the gravity some heroes face crashing down on them when trying solely to do the right thing. Penance is a broken man with a hero mentality fighting to stay in tact as depression, guilt, and persecution tale over his psychy. Definitely read his bio in the marvel database for more details. He is by far one of the darkest yet most compelling dark heroes to emerge out of marvel's conflicts.
Gambit My personal favorite mutant tied with nightcrawler and wolverine. Overall i just love Remy's character, story, style, powers, hell the whole damn package! The Gambler with an explosive edge. Gambit will always be a fan favorite of the X-men universe and to be honest im surprised he hasn't gotten more screen time in the cinematic universe along with nightcrawler because they are like primarily two of the benchmark favorite 90z babies mutants and two of the most iconic in the entire series.
I love em all for different reasons but thats am earful lol