I was once asked to sort a singly linked list in an interview, and the bubble sort was the only one I could think of at the time. This was a small part of a larger coding test that I think was based on a problem they actually ran into, which a previous employee had solved badly. I got a low-ball offer and turned it down. It wasn't until a couple of years later that I thought about that problem again and realized a merge sort would have been perfect.