5. Hulk
The Hulk's reputation as a force of nature precedes him. He's literally known as The Incredible Hulk. However, his portrayal in the MCU has been a little less incredible than fans would have liked.
The Hulk first appeared in his own self-titled movie in 2008, played by Edward Norton. Mark Ruffalo would go on to play him after that in every Avengers movie and the various supporting roles the character would have after that. Fans have been appreciative of both actors' portrayals, but some of the writing revolving around the character has been inconsistent, making his power levels hard to gauge.
Early on in his MCU days, the Hulk was as incredible as you'd expect. A hulking brute of a creature that reared his head when Bruce Banner got angry, he could destroy just about anything with his bare hands. Without the human emotion to keep him in check, he could easily go from an ally to a threat in seconds, which is something that the first Avengers movie highlighted very well. However, as he continued to appear, the MCU would depower him, relying on him for comic relief and often providing convenient reasons for why he could partake in any fights.
The Professor Hulk iteration we saw in more recent Avengers movies haven't gone down well, because one of the reasons that the Hulk was so effective was his anger. Take that away and you just have big and green Bruce Banner.
Nevertheless, the Hulk is pure brute strength, and when he's at his best, he might just be the most physically dominant Avenger on this list.