New Player, Suggested DLC?

Hi all. When Stellaris came out my brother finally convinced me to try EU4, so I've been playing his copy through the Steam family share system. And I love it. I started with Castille to get a feel for the game, then after about 60 years into Castille I ditched that game and started playing Brandenburg, because I love Germany (my family is very German in heritage). After playing out the first 50 years like 10 times I finally got a hang of the Economics and diplo aspect of the game... Kinda, and now am running my first play through as Brandenburg -> Prussia -> (hopefully) Germany.

So my question is... What DLC should I buy with this game to get a full experience out of it, without spending an arm and a leg. I like the Asian and European histories, but could care less about the Middle East or Africa beyond colonialism. I read that the complete edition is not everything, so a core list of really good DLC or suggested mods would be great.

Thanks!