Watch a prequel first? Which/why?
I see questions like this asked all the time: "Should I wait for/watch the prequel to _____ before I watch ____?" but have never seen a satisfactory example given. The very term obviously implies a story taking place prior to an already released work of fiction but written afterwards. I can't think of a single example where it would be a good idea to watch a prequel before the spawning work, as a prequel's very nature is to appeal on fan service merits, and one can't be a fan of a work they haven't seen yet.
Can anyone provide an example where watching a prequel first provides a more satisfactory viewing experience and why?