I'm not sure who the absolute best is, but there are often some popular ones on fanfiction platforms. You can usually tell by the number of reviews and favorites their stories get. Some authors might be really good at capturing Meredith's complex personality, while others might shine in writing Finn's character. You have to explore different stories and see which ones resonate with you the most.
Honestly, it's a matter of personal preference when it comes to the best authors of this fanfiction. There could be an author who focuses on the medical aspects of their relationship, like how they handle cases together. This type of author can make the medical jargon and procedures seem exciting and relevant to the story. Then there are those who are more into the romantic side, creating beautiful, swoon - worthy moments between Meredith and Finn. You really need to dig in and read different works to find the authors that suit your taste.
There are many talented authors in the Meredith Grey and Finn Lemon fanfiction community. However, it's difficult to single out just a few as the 'best'. Some authors are great at creating emotional and heart - wrenching storylines. For example, there might be an author who writes a story about Finn's struggle to win Meredith's heart back after she has second thoughts. Their writing might be so vivid that you can really feel the characters' emotions. Another type of great author is one who can write really engaging dialogue, making the interactions between Meredith and Finn seem natural and interesting.