Sylvia Plath is best known for her novel "The Bell Jar," which explores themes of mental illness and identity. Published in 1963 under the pseudonym Victoria Lucas, the semi-autobiographical novel reflects Plath’s struggles with depression and societal expectations. Her poignant and honest prose resonated deeply with readers, marking her as a significant voice in confessional poetry and feminist literature. Plath's legacy continues to influence writers, and her works remain a vital part of discussions on mental health and female experience.