I am not an Marvel Unlimited subscriber so some of my recommendation may not fit, but if you familiar with the MCU, but have not read Marvel comics I would go with comics that inspired the movies. The movies boil down the essence of the stories, but they are not the same plots so you should not feel like you are reading the same thing.
If you liked Captain America: The Winter Soldier read Ed Brubaker's run on Captain America. This is the story arc hat brought Bucky back to the Marvel Universe, and it is probably the best Captain America run of comics. It also dovetails nice into my next pick.
If you liked Captain America: Civil War why not read Civil War the comic. The story in the book is not that similar to the plot of the movie, but they share a lot of the same notes. Iron Man relationship with Spider-man works in the movie, and the thought behind starts in this comic.
The best part Thor: Ragnorak is the Sakaar section which is basically a short version of the Planet Hulk.
If you like Guardians of the Galaxy 1 & 2 read the Dan Abnet & Andy Lanning run on Guardians of Galaxy. It is the reason why these characters work on screen. They essentially revamped the Marvel cosmic landscape. If you want some background for that run read these books.
Annihilation: Nova which leads to Annihilation which leads Annihilation Conquest (you will be familiar with the main villain of Conquest if you have just seen the movies).