Lausanne, my hometown! Not a very big city, but very pleasant to live and very lively and culturally active. It sits on the shores of the beautiful Lac Léman. Mountains and outdoors are not very far away, so you can hit the slopes to ski in less than 1-hour drive. Or you can reach the countryside by bike very quickly !
It’s very uphill so riding a bike is quite demanding, but on the other hand it creates many sightseeing opportunities. Architecturally speaking, it has a few gems worth seeing. Typically it hosts the IOC (International Olympic Comitee) headquarters which is an amazingly interesting building.