I always travel by rail in Europe. I have found that rail europe is good for getting rail passes, but little else. However, the best luck I have found, and getting a good fare besides, is to buy it there at the train station.

The second class sleeper can be fun too... had one from Barcalona to Zurich. Only myself and a woman who spoke excellent english (and also spoke French, Italian, and German). We spent the whole night talking and sharing a bottle of wine. An excellent adventure.

Another time from Zagreb to Munich, I shared a second class sleeper with a gentleman from Zagreb. He knew no English, and a little German. I knew only a little Croatian and a little German... but we had fun talking about families and playing cards....and a bottle of wine. It is what you make it....