1) The Pevensies (from the Chronicles of Narnia). They're siblings, it's pretty stereotypical, but I like them anyway. They end up becoming kings and queens together, and I think I like them even better when they're grown up than when they're little kids. The Horse and His Boy is my favorite in the series, and they have great chemistry there. It's rare to see siblings crowned beside each other, so I liked that.
2) Gemma Doyle, Felicity Worthington, Ann Bradshaw, and Pippa Cross (from the Great and Terrible Beauty series, Libba Bray, ILU). Unlike a lot of main characters, I spend a lot of time ridiculing them and being ticked off at how annoying they are sometimes. This might not sound like a positive, but I do this because each character is incredibly and uniquely flawed. They could be a real group of friends. They have fallouts over stupid things and power struggles and other things teenage girls fight about, except with more magic and death. Very realistic characters and they have good chemistry together, even though they all hate each other in the beginning.
And, short post again, but I'm brain-dead and hopefully, you guys have better examples than me. Happy Friday!