Something I came across a while ago and found quite interesting was a punctuation mark known as an ‘interrobang’:

It’s an obsolete mark now; it was intended for use as a condensed version of the ‘?!’ we use today, but didn’t catch on. What I like about it is that the combination of question mark and exclamation mark creates an elegant form of its own; also I love the name – ‘interrobang’ has a really quirky and dynamic sound to it.