In Zermatt you MUST take a helicopter flight around the Matterhorn. The flight takes 20min and costs 210 swiss francs. You won't regret spending a cent. It was the most amazing experience and an absolute highlight of my month in Europe. The flight leaves from Air Zermatt which is at the end of town, but if you head to the information centre at the train station they'll give you directions. Try and book a day before you go because they like to fill the helicopter up.
Enjoy.