Jane Foster when she was the wielder of Mjolnir. Not for anything about her personally, but the fact that Thor was treated as a codename. It's the dude's actual name, it'd be like if Sam Wilson went around introducing himself as Steve Rogers when he took the Captain America mantle. It's happened a few other times like with Eric Masterson, but at least he had the excuse that for most of the time he used the name he and the actual Thor were sharing a body.