Michael

Michael is the eldest of the four archangels, God's firstborn. It is said that he will banish Lucifer back to hell when they meet on the battlefield in the wake of humanity's apocalypse. 

To come to earth he needs a vessel like any other angel. The preferred option is Dean, with Lucifer looking for Sam, the slightly rebellious younger brother. The show doesn't hold back in highlighting the obvious similarities between Michael and Lucifer compared to Dean and Sam. Nevertheless, when Dean refuses Michael entry he uses Adam, the Winchesters' half-brother.

When about to face down against Lucifer at the end of Season 5, Castiel sends him back to heaven by using holy fire, giving Dean time to help Sam who is trapped inside his own body. When Sam is able to free himself for long enough to combine the horsemen of the apocalypses' rings and create a hole into the cage in hell, Michael returns to try and stop him, but they are both thrown into the depths of hell.

Technically in the fifth season, Michael takes two vessels: Adam, the Winchesters half-brother and a young John Winchester. He is Adam during the attempted face-off with Lucifer, who is in turn using Sam as his vessel. However, when Anna goes back in time to try and kill Mary Winchester, to stop her giving birth to Dean and Sam, she is smited when Michael uses John as a temporary vessel for intruding in the grand plan of heaven.