There are fanfictions where Bulma creates a new technology that has an unexpected impact on her relationship with Vegeta. For example, she might create a device that can temporarily give Vegeta new powers, but it also causes some humorous or emotional situations between them. Some fanfictions also explore what would happen if Vegeta had to protect Bulma from a new, powerful enemy that is specifically targeting her because of her intelligence and the technology she holds.
In some fanfictions, the focus is on the early days of their relationship. For instance, how Vegeta, who was initially so aloof and proud, gradually fell in love with Bulma. It could show their first meetings from a different perspective, like how Bulma saw Vegeta not just as a powerful Saiyan but also as a complex individual with his own struggles. This type of fanfiction can be really engaging as it delves deeper into their characters and the development of their relationship.
One interesting fanfiction could be about Bulma and Vegeta going on a secret adventure together. Maybe they discover a new planet and have to work together to survive. Another could be a story where they deal with family issues related to their son Trunks in a very different way than in the original series.