One great Anakin Skywalker fanfic is 'The Fall and the Redemption'. It delves deep into Anakin's internal struggle between the light and dark side. Another is 'Anakin's Untold Journeys' which explores his relationships in a new light, especially with Obi - Wan. And 'Anakin: A Different Path' presents an alternate timeline for his character that is really interesting.
One idea could be a story where Anakin and Ahsoka are reunited after a long time apart. Maybe Anakin has been on a secret mission and Ahsoka has been exploring new parts of the galaxy. When they meet again, they have to work together to face a new threat that is endangering the Jedi Order.
There are some out there. However, the quality can vary greatly. Some might focus more on the romantic aspects between Anakin and the members of the harem, while others could be more action - packed with the harem aspect being a secondary plot. You really have to dig through different fanfic platforms to find the ones that suit your taste.
I really like the fanfic 'Anakin's Guidance for Rey'. In this story, Anakin, as a Force ghost, appears to Rey after she has started her Jedi training. He gives her advice on how to deal with the dark side of the Force, based on his own experiences. It has a lot of great dialogue and shows how Anakin has grown in his understanding of the Force even after his death.
There are fanfics where Anakin's death is due to the consequences of his past actions. His use of the dark side might have weakened his body over time, and eventually, his health fails him. This could be a slow and painful death, with him reflecting on his life and all the mistakes he made. He might even try to make amends before he passes away, reaching out to those he has wronged.
One interesting Anakin Skywalker fanfiction could be one that focuses on his redemption arc in an alternate universe. It might explore how he uses his powers for good in different ways, perhaps teaming up with unexpected allies.
A fanfic titled 'Jedi Allies' is also quite good. It focuses on the friendship that could potentially develop between Anakin and Ayla. It has some great action scenes and also delves into their individual characters' growth within the story.
One common theme is regret. Anakin often has many things he regrets in his life, like leaving the Jedi Order or harming those he loved. His crying in these fanfics can be a manifestation of that regret.
A common theme is the fall to the dark side. It explores how Anakin gradually becomes Dark Anakin, his internal struggles, and the events that lead to his transformation. Another theme is redemption. Some fanfics try to show a way for Dark Anakin to come back from the dark side.