Q: what's the wackiest time signature you've ever written in
A: it sounds like you're looking for something where the time signature stays the same, even though that's definitely not the wackiest you can do with time signatures, nor is it the wackiest i've done with them. However, if we're only including non-changing time signatures then the answer would probably be the 'violence' outtro of ball and stick which should be 13/16 if i remember correctly