Who was the most selfless character on How I Met Your Mother?

The character who is considered to be the most selfless on How I Met Your Mother is Marshall Eriksen, portrayed by Jason Segel. Throughout the show, Marshall often puts his friends' needs and desires before his own, and is known for being a supportive and caring friend.

One notable example of Marshall's selflessness is in season 2, when he gives up his dream job at a top environmental law firm in order to stay in New York with his fiancé Lily, who is struggling with the prospect of leaving their friends and the city they love. Another example is in season 5, when Marshall offers to give up his job as a corporate lawyer to work for an environmental advocacy group, despite the significant pay cut and the fact that he has just become a father.

Marshall's selfless actions and his loyalty to his friends make him a beloved character on the show and an example of true friendship and selflessness.