I personally think that Euro looks pretty good as a design object, but I am also of the opinion that change is good. Barbara Bernat, an imaginative art student from Hungary, proposed an amazing concept for refined Euro banknote series, which I would gladly see being issued to the real-world.
In her's vision, the notes could feature European animals on one side, and related species of plants on the other. The artist put together a visualization, in which we can see neat hand drawings of deers, wolves, and lizards as well as various leaves and fruits.
Overall, the money has a very clean design with simple typography and artistic representations of animals and plants. That surprising switch from historical architecture and art to peaceful nature-inspired theme is the part that I like about Bernat's project the most, but all the rest is really amazing, too.