I think the Russo's are pretty boring direction-wise honestly. The likes of Civil War, The Winter Soldier and Infinity War are enjoyable, but don't really stand out from a directorial point of view. If you'd ask me what is "typically Russo Brothers", I wouldn't be able to give you an answer.
I would say my favourite is Taika Waititi, who really directed the shit out of Ragnarok. It's impressive how much of his own style and mannerisms he was able to include in Ragnarok. Outside of that, Ragnarok also has many really inspired directorial choices. And also, I will never not be impressed how Waititi took the most boring character in the entire MCU and turn in the best MCU movie.
After that comes James Gunn. Because while I really dislike the first Guardians of the Galaxy (the second is much better, IMO), he was also able to really shape those movies to his vision. GotG 2 is also the only MCU movie that really nails it's themes IMO.
Finally I would say Coogler is third. Black Panther might have some issues with the third act, but the first two acts are excellent and again, it's impressive how much of hinself Coogler was able to put in the movie. I would've never expected a MCU movie to really try (and mostly succeed) to tackle racism like this.
EDIT: Also special mention to Joss Whedon, who pretty much created the template for what we now see as a Marvel movie with the first Avengers (together with Feige of course). While I'm a vocal critic of that template, it's still an impressive feat.
One of my very few issues with Ragnarok is that the amazing comedy overshadows a couple moments that should otherwise be very emotional.
I'm mainly referring to the completely random deaths of the Warriors Three. Those were important characters in the original Thor and it bothers me that they were killed off like that, with basically no mention of them after.
Outside of hardcore comic book fans, nobody cares about the Warriors Three. They were as disposable as Kat Dennings' character, and I say this as a huge Ray Stevenson fan.