Acqua di Gio is a casual/daily/office/anytime/anywhere scent. Many wear it for that purpose. Don't expect to stand out from the crowd!
Armani Code is a tad more formal to me. I'd wear it out any season but fall weather wear is its best.
Armani Attitude, despite the name, is fairly tame. I'd wear that to the office. It's like Burberry London which I wear to work a lot. Cool weather scent.