We travelled by train from Llandudno Junction to Switzerland last Saturday and spent every day there on some train or other, so I have a lot of pics and have learnt rather a lot about how to run a train system extremely well. Mind you, as my other half sagely noted, it helps when you don't have to drop everything to fight a couple of world wars or fund a Navy...
The Swiss operate two different train systems, as well as hosts of tram systems in their towns. Essentially, they use standard gauge systems for high-speed trains and drill holes through any big lumps of land which get in the way, so their big trains run straight, flat and fairly fast. They also operate a 'narrow gauge' system - slightly more than 3' wide - and all trains run on electrified routes.
In terms of climbing and descending, the narrower gauge system (which uses full-width coaches BTW, so you don't realise it's narrow gauge) excels at gradients you would otherwise only expect to see in theme parks and many are fitted with regenerative braking systems, which feed back into the various overhead lines. The narrower gauge also excels at very, very tight bends whilst clinging to the sides of sheer rock faces.
What the Swiss do very well, however, is provide information. In buckets-full. In each mainline coach there are LED screens which tell you which stop you're approaching, what the eventual destination of the train is, which coach you're in, what connections there will be at the next station and whether the Loo is occupied (that last's important, since the one thing the Swiss can't get right is providing working toilets on their trains).
But we travelled on Virgin, Eurostar, Thalys, DB CNL and CH, including Bernina, Glacier, Gornergrat and the odd few in between. Main finding: a few little things could improve our network immensely, the Swiss aren't perfect but they're good, Thalys is seriously fast and DB (the German network) are truly, truly awful. But give me train any time over 'plane.