Contains the following shows: Arrow, The Flash, Vixen, Constantine, DC's Legends of Tomorrow and Supergirl (for now, more will be added as they are released).
Comments are welcome in order to make this list the most accurate possible.
• "Arrow: Blood Rush" is actually a BOSE commercial in six parts lasting about six minutes in total (available on Youtube). While they are not really mandatory, they should be watched between episode 5 and 6 of season 2.
• "The Flash: Chronicles of Cisco" is a four part short also available on Youtube, not mandatory.
• Constantine: Episodes can be slotted in at will as long as you watch them before S04E05 of Arrow. They're not mandatory as the show is somewhat inachieved but you might enjoy the character. Update: An animated series being planned, the story might continue from where the show stopped.
• DC's Legends of Tomorrow: I included the first special episode before the first episode because this special kinda introduce the show explaining where the characters are from (in a "making-of" style) whitout much spoilers while managing to refresh our memory about them.
• Supergirl: Episodes can be slotted in at will until S01E17 (included) as long as they're seen before Arrow S04E19. Episode 18 is the first time Supergirl get to meet a character from the Arrowverse (The Flash). Side note: For Season 1, you may encounter a wrong episode order depending on the sources (only some, I didn't meet this problem): the right order would then be 1-2-3-5-4-6 to end, but it is not a big deal as it actually doesn't change much.
• "Freedom Fighters: The Ray" will be integrated as soon as we have informations about it.
• "Constantine" (Planned animated series) will come up at some point, it might continue the story from where the TV show stopped it, more news to come.
THIS LIST WILL BE UPDATED PERIODICALLY. (Last update: 2017-03-09)