Really the weirdest? If the weirdest is really what you're after I would say an ATM. Those usually run Windows and when I saw one running Linux I was very surprised. But it isn't really that weird to find linux in places that aren't obvious. So much so that now I expect to find Linux if I find a device where I assume there is a high level language used to maintain it (and surprised if it is something else).
A few quick examples of places Linux is gaining ground that may not be obvious to the average consumer: