I had a wonderful lake view from a junior suite at the Lausanne Palace, I remember - you could see the mountains ringing the lake, going pink in the sunset - delightful.
If the OP is not bothered which side of Lac Leman he stays at, then I'd also recommend the Royal Parc Evian - 2 hotels (one is 4 and the other is 5 star) - good indoor pools and Evian is a far more attractive place to stay than Lausanne.