Last year I was on the newer regional train to/from Andermatt starting in the Vorderrhein valley. I was surprised to find out that the windows actually open on the newer RhB trains as well.

As Fredrik74 mentions, the Interrail/Eurail pass (depending if you live in Europe or not) is a pretty excellent deal, so long as you make sure to take long enough journeys. Don't use it on going from the airport to downtown in Zürich, for example.