Crusader Kings series
Europa Universalis series
Hearts of Iron series
Victoria series

Hmm..
Defenders of Ardania
http://store.steampowered.com/app/73060/?snr=1_7_7_230_150_1
Is " Set in the rich fantasy world of Majesty, but with a twist."
Apparently - so.. part of the Majesty series or not, do you reckon?

GamersGate agrees with you, as it has a Majesty Collection Bundle, which contains Majesty 1+2, Defenders of Ardania and Warlock: Master of the Arcane.

both Defenders of Ardania and Warlock: Master of the Arcane are considered separate series on wikipedia, which I see a more reliable source than steam or gamersgate. Yes, they do share the same universe, but still different series. Such as listing "Baldur's Gate series" and not "Forgotten Realms series"

Anyone who played those games are welcome to convince me otherwise though :p

added Crusader Kings II
added Europa Universalis II
added Europa Universalis III
added Europa Universalis: Rome
added Europa Universalis IV
added Hearts of Iron II
added Hearts of Iron III
added Victoria II

for obvious reasons, I am not adding the thousand DLCs. If the games are released with missing DLCs, then I would consider adding them

What about the 2 games that are subtitled 'A Hearts of Iron Game'?
Arsenal of Democracy: A Hearts of Iron Game
http://store.steampowered.com/app/42850/?snr=1_7_7_151_150_1

Darkest Hour: A Hearts of Iron Game
http://store.steampowered.com/app/73170/?snr=1_7_7_151_150_1

added Arsenal of Democracy: A Hearts of Iron Game
added Darkest Hour: A Hearts of Iron Game

also Hearts of Iron: Iron Cross

Europa Universalis:
Europa Universalis II Asian chapters
for the Glory
march of the eagles
sengoku
two thrones
crown of the north.


cities in motion
cities in motion 2

sword of the stars complete collection

This is only for series that already on GOG. March of the Eagles, Sengoku and Cities in Motion are nowhere on GOG.

Isn't that an expansion for EU2?

aren't march of the eagles and sengoku sort of part of the Europa Universalis series ?
i thought asian chapters was a remake with extra countries and a bigger map and some other changes.

They might be Paradox-developed grand strategy games like Europa Universalis, but they're not part of the Europa Universalis series.

Ys: The Ark of Napishtim
http://www.gog.com/wishlist/games/ys_vi_the_ark_of_napishtim

Ys Seven
http://www.gog.com/wishlist/games/ys_seven

Ys: Memories of Celceta
http://www.gog.com/wishlist/games/ys_memories_of_celceta

I'm not sure if damien accepts games that haven't been localized yet in English (Though he has included some German-only versions of Settlers).

please be more clear. Which game should be added to which series for what reasons?