I hate it when they turn up with some new shiny that you just KNOW isn't going to integrate with the rest of your network.
One salescritter tried to persuade me to install massive MFP's in student labs, knowing full well that anything with less armour than a battle tank isn't going to survive that environment - let alone a big, fragile white shiny with lots of trays to jam and buttons for people to mash randomly.
The following day, said shiny turns up on the back of a truck.
"Go on, kick the tyres and see what you think", he said to me over the phone - the usual salescritter language for "just print off a couple of test sheets and sign here".
After he rang off, I started moving boxes of paper to where the printer was lurking.
"Are you really going to kick the tyres ?" one colleague asked.
"No. I'm going to smash the driver's window, break the steering lock, hotwire it, take for a few donuts round the car park and then set fire to it !"
Poor critter nearly choked when he collected it and checked the page count.
Hey, I needed a new set of OpenVMS and Cisco manuals, what can I say ?