"How you judge me will come in time..."
Roland Deschain, also known as Roland of Gilead, also known as The Gunslinger.
He is, obviously, the main character of the Series. At the beginning, he is the last of the Gunslingers, chasing after the Man in Black. At present, he is travelling with a ka-tet consisting of himself, three other humans, and a bumbler.
His goal is to save the Tower. After he saw it in a vision, he realized that it was his true goal, and he started out for it. In his mind, the Tower is first and foremost. He knows of its perils, and understands that it needs to be saved so that everything stays together.
For a long time he was loveless, and he has sacrificed himself and others for the Tower his entire life. His state of mind allows this, and keeps him going.