Dolittle, Entebbe, Tehran, Pickett’s Charge, ...
I’m thinking when we shot down Yamamoto in his bomber - that was pretty “audacious”. 1000 miles in modified P-38’s.
Amelia Earhart - that was an Audacious Plan.
I think the earlier poster with the moon landings though might have the most Audacious Plan. Especially with the technology they had back then. (Well - no technology really, until they created it for the moon mission.)