Nimona is great LGBT representation, with a queer coded main character and an actual gay relationship. I don't know that its specifically transgender representation, but definitely worth the watch!
Technically not transgender representation since Nimona is a shape-shifting enby creature from the outset and not someone who was assigned a gender at birth and later transitioned away from it, but she does shapeshift into a little beggar boy in one scene so I think it still counts. =3
I consider non-binary identities raised with an enforced binary socialization like myself have every reason to identify as trans. That’s not explicitly displayed in Nimona, but I can confirm that I felt represented and had an incredibly emotional reaction to the film.
Also: there is at least one trans pride flag colors not-so-hidden in the movie. 🏳️⚧️
Doom Patrol has several episodes that feature a sentient, genderfluid street that teleports around and acts as a Brigadoon-esque haven for LGBTQ folks who are outcast from polite society, so that's a fun thing.
Haven't watched it but my friend's really into Umbrella Academy. In season three Elliot Page's character transitions to male and I've heard it was handled well.
My Life As A Teenage Robot. People believe the main character relates to a lot of transgender folks, along with the creator of the show supporting the idea and happy that there are people who relate to the main character.
Gay ally chipping in here, but I really enjoyed Pose. The first season has some problems (like shoehorning in specific famous actors to get people to start watching it..), but the second and third seasons almost exclusively focus on the trans and gay characters and it's really nice to see so much trans representation.
Jessica Jones season 3 features a trans side character - Jessica's assistant. It's only a very small role, but the character packed a lot of personality into any scene she was in, and also helped drive some of the season's themes home, imo.
In a way, the smallness of this role was why I liked it - I want to be seeing more trans main characters and stories that are explicitly trans, but representation also means more trans people just existing in the world, as themselves.
Cloud Atlas doesn't have a trans character, per se, but the entire movie is based on the premise of reincarnation and souls persisting through time. And, being directed by the Wachowskis is an implicit seal of approval.