I've stayed in Geneva twice for a single night each time. The Suisse Hotel is perfect for that one night stop. The proximity to the train station is ideal for a morning getaway. But it's only a 3 block walk to Lac Leman. I was able to arrive in the afternoon, take a stroll down by the lake, maybe a short boat ride, then find a nice lakeside dinner before returning to the hotel for the night.
Directions: Across the street from the train station. There is an underground tunnel to enter the station on the pedestrian street adjacent to the hotel.