What are cheap travel destinations from Geneva ?

Coach, train or even plane.

Well...you have all of Switzerland at your fingertips. Buy a half-fare card to cut significant costs.

If you get a day card ( Tageskarte ), some trips are good on the PostAuto.

Day card valid of course on normal bus, train, boat etc.

For ideas:

what are the best places to show to guest??

By Train:

http://www.sbb.ch/en/travelcards-and...r-tickets.html

Italy:

http://www.trenitalia.com/cms/v/inde...003f16f90aRCRD

Paris: http://tgv-lyria.tgv-europe.ch/en/

By Plane:

http://www.easyjet.com/en

If you are a Geneva resident (same as what jrspet's suggestion):

http://www.ville-geneve.ch/demarches...urnaliere-cff/

Skyscanner.net

Pick your airport, then you can choose "Fly to anywhere"and it pulls up all the flights form the airport starting with the cheapest...