Geneve, Lausanne or Bern?

Bern hands down for me. Not sure about museums though.

a.) genève and bern (lake geneva riverfront & rhône river, geneva golfclub, the old town of bern, river aare, the swiss parliament)

b.) lausanne and montreux (the IOC-museum, chateau chillon, century old ***** hotels in the mountains of the montreux area)

'super from munich in deutschland

All 3 towns have fine, but very different museums.
http://www.berninfo.com/en/page.cfm/Kultur/MuseenGalerien
http://www.geneve-tourisme.ch/?rubrique=0000000003
http://www.lausanne-tourisme.ch/view.asp?domId=64285&language=E

Bern has by far the biggest and best preserved (still living) medieval city center. It will be full of life Wednesday and rather deserted Sunday. But the 4 lakes with public boat traffic are about 40 km away (Lake Thun, Bienne, Neuchatel and Murten), whereas Geneva and Lausanne are on Lake Geneva.

Fine weather: as everywhere in Switzerland, a lot of gems are situated between the big towns:
Entirely walled (free acces to the city walls) medieval Murten
Roman theatre of Avenches
Castles of Neuchatel, Grandson, Yverdon, Chillon, Prangins (National Museum), Coppet, Gruyeres (with cheese diary and chocolate factory nearby)
Boats plying the lakes between Murten - Neuchatel - Solothurn, Murten - Neuchatel - Yverdon, Geneva - Lausanne - Montreux