It's been a long time since I've come across anything worthy enough to post here, but I think this one tops the list. An end user had a laptop with an extended life battery. He didn't want to lose it or for someone to steal it, so he used Liquid Nails to glue it to the bottom of his laptop. Long story short, the tech in his area had to bring the system to our office to repair it. It took us a few hours to finally pry the extended battery off, pretty much destroying the bottom of the laptop case in the process.
This is a picture of the bottom of the laptop and the extended battery. The regular battery had already been removed:
Here are closer pictures of the damage: