Mine tend towards the latter for both internal and external and only get a little more expository if it’s a closedown period and I’m adding leave to one end of it, but that’s a simple “The organisation is shut between X and Y. For emergencies during this time please contact Team. I am on leave between Z and B and will not be accessing my email during this time. Please contact Email Address if your enquiry is urgent otherwise I will attend to your email as soon as is practicable upon my return.”
If you’re looking for a classic OOO message, this one is for you. Perhaps you work an industry that values directness and getting straight to the point, and playfulness may be off-brand. This response covers all of the most important bits of information every OOO needs: the date you will return to the office, when they can expect a response back, and who to contact in the meantime. That’s it!

I agree about the out of office reply. Made me laugh. Given that I work a high stress job, I can always use some laughter, so I actually don’t mind it.
Does your company publish blogs or offer downloadable ebooks, reports, or case studies? If so, add a P.S. to the end of your vacation message linking your readers to some content they can learn from or engage with.