One of the major ways Elementary stands out from other Holmes adaptations to me is how they wrote Watson. Like it would've been so easy to write her like any other Watson, brilliant, yes, undoubtedly, but forever attached to Sherlock. Watson is there because Sherlock wills it so, because Sherlock needs a rock and because Sherlock Holmes is a man forever in need of a partner. Usually.
But they broke that. They said this is Dr Joan Watson, and she is incandescent and ruthless. She's a surgeon and there's an episode where Sherlock says surgeons have a healthy dose of god complex and you think sure buddy and then Joan threatens Moriarty in the middle of a restaurant and you go, huh. She learns to pick pockets and watches out of boredom. She changed careers over and over again till she found the one that fit. She became a detective and could and would absolutely kill a man and vouch for someone killing a man because it's Sherlock and she loves him very much. She's a partner, in the very literal sense. She kept track of murders as a teenager. She enchanted the most dangerous woman on the planet and EARNED her protection. She's a cancer survivor. She threatens gangs and online hacker conglomerates in free time. She's a mother. She's half of two people who love each other very much. She moved across oceans for him and she would do it again.