[healsdata]

The triangle design is pretty cool; I can't recall ever seeing one like that in the wild, but it looks like it's been a possibility since '97.

[bartvk]

I received a round Global Forever 2018 stamp, which I found pretty cool. But the most extraordinary stamp I received, was from Belarus. It had a strawberry smell.

[ornornor]

I think France issued a baguette smelling and a croissant smelling stamp not too long ago.