Thor
Abilities: Members of the Asgardian Royal Family are not actual gods, per se — but they're as close to gods as you can get. Thor is ridiculously powerful, such that only his father and older sister (both dead) would surpass his strength. He's not immortal but he's close to invulnerable, considering he endured the full force of a star and survived.
Thor is most powerful when he can channel his powers through an enchanted, loyal weapon forged on Nidavellir, like the hammer Mjølnir or the axe Stormbreaker. But as the God of Thunder, he can also summon and harness pure lightning.
Power scale: 20. Thor is so powerful that filmmakers are constantly looking for ways to handicap him. In "Ragnarok," they destroyed his hammer. In "Infinity War," they completely took him out of the picture for most of the action — and when they put him back in, a suitable weapon in his hands, he was mere moments away from killing Thanos. In "Endgame," they gave him severe symptoms of alcoholism and depression, undermining his ability to fight effectively.
If Thor were at peak potential during most of the Avengers' battles, they probably wouldn't have been very long. In fact, he didn't even discover his true potential as the God of Thunder until "Ragnarok." There's no telling how powerful he truly is, because Marvel is constantly putting obstacles in his way — and even with those obstacles, he's easily the second-strongest hero we've seen.