This shirt is dark, has two breast pockets, and does up with dark buttons.
In The Werther Project (10x19), Dean wears this shirt when he passes out watching Speed 2: Cruise Control after a long night of killing vampires.
In Thin Lizzie (11x05), Dean is wearing this shirt the first scene we see him in the Bunker. He keeps it on for the trip to Fall River, and their initial investigation there – until the second murder of the episode takes place.
In Rock Never Dies (12x07), this MIGHT be the shirt that Dean is wearing when he and Sam meet up with Castiel and Crowley at the hotel and check out Vince Vincente’s suite.
In Ladies Drink Free (12x16), this might be the shirt that Dean is wearing when they say goodbye to Claire at the end of the episode.
In The British Invasion (12x17), Dean wears this shirt when Eileen comes over to tell them about how she tracked down Kelly Kline.
In War of the Worlds (13x07), Dean wears this shirt when he is chilling in the Bunker, after they’ve interrogated Ketch. He wears it for the rest of the episode.