Any creative ones?
Back in the iPod era Apple had a gallery of examples on their website to get people inspired when they wanted to do the free engraving. I always thought they were really clever.
My 5th gen iPod Classic and my 3rd gen iPod Touch I just went boring and put my name on them (they were both Christmas gifts). I put “AwesomePods” on my AirPods Pro case.
I would’ve put something similar on my AirPods Max if I had bought from Apple, but got them at a heck of a discount from Best Buy.