#1 - Unless you came in early - your are definitely cutting out early. Lots of people slide out the door before 5 but don't go around announcing it by saying something cheesy.
#2 - Goodnight? What is this? 1950?
#3 - Goodnight is for when you are going to bed - not 5pm to your co-worker. It's not even dark yet. Dumb!
What are your pet peeves?