The 21-year-old Brit says she loves the character the 53-year-old plays in the movie Ghost World.
In her monthly column for US magazine Nylon, Geldof writes: "After repeatedly viewing 2001 cult classic Ghost World, I've come to the conclusion that I would definitely fall for Steve Buscemi in his role as hapless, obsessive, record-collecting loner Seymour, one of the most depressing geeks ever to light up the screen."
The actor - who recently won a Golden Globe for his role in the TV series Boardwalk Empire - played just one of eight movie characters that Geldof says define her ideal man.
"I've actually realised that I have an even weirder taste in men than I thought," she says, after watching some of her favourite films, including The Breakfast Club, Heathers, Buffalo 66 and Harry Potter.
"They all tend to be skinny, angst-y bad boys with great one-liners and a variety of mood disorders."
The daughter of Bob Geldof and the late Paula Yates also says: "Tortured geniuses are another weak spot for me."
Her ex-lovers include actor Eli Roth and rocker Max Drummey, to whom she was briefly married.