Feels like treasure

Today I was just counting my change in my wallet when I found a Peter Rabbit 50p coin to add to my coin collection, wow I was very very happy to say the least. It felt like I'd found treasure as I haven't got one of these coins in my collection.

I've been adding different coins to my collection for the last 20 years not very often though as I only add coins that I find fascinating and with which I get through my change usually.

What does everybody else collect?