very good, great, excellent, really good
Hacía un pan buenísimo, pero hace tiempo que no se usa.
It used to make excellent bread, but it hasn't been used for a long time.
— Nicky, la aprendiz de bruja (1989)
Y además prepara un té buenísimo.
And she also makes a really good tea.
— Incontrolable (I Swear) (2025)