Far too many to list here... we have many circulation coins that collectors want to add, not for "metal value"(ie silver/gold), but because of scarcity.

With just under 6.2 million in circulation, it isnt particularly rare at all.... but take to holy grail of circulation coins here in the UK, the 2009, Kew Gardens 50p(£0.50) - with just 210,000 ever released in to circulation, they now fetch £150+ on Ebay. If you find one of thise kn your change, youve done alrifht for yourself