Honestly nickels and dimes, and maybe even quarters, should go too. It's ridiculous that we don't have $1 and $2 coins in widespread circulation in the US (we have a $1 coin but nobody uses it).
Sorry Europe and Canada, $1 and $2 coins are just absolutely terrible. I never want to have to think about where my change is. Bills are much lighter than coins and stack with the rest of the bills.