Gee/Gee whiz/Gee whiskers/Gee willikens etc
Gee, together with all the bits and pieces that are often added to it, are inoffensive exclamations of surprise that are of American origin from the mid-to-late 19th century. They are really forms of minced oaths, euphonic abbreviations of the exclamation 'Jesus!' which was frowned upon as taking Jesus Christ's name in vain. The origin and meaning of all the add-ons like 'whiz, whiskers, willikins' etc. are unknown, although theories abound. Some sources claim they derive from Irish Gaelic brought to America by Irish immigrants, but this etymology remains unproven.