Shakespearean Insults are always fun, and you can get them on band-aids and coffee mugs, in do-it yourself insult kits, and more. This use of them in an office context is pretty well done:
Here's a day-by-day Shakespearean Insults 2015 Calendar.
This Shakespearean Insult Generator has been around since early internet days. This generate-your-own version is newer and has a heck of a lot of possibilities - choose one item from each of the four drop-down columns.