One of the most interesting/unique user interfaces for a train ticket machine I have used in a long time are ones you still occasionally see in French train stations [1].
Rather than a touch screen or buttons, you use a wheel much like the original ipod. To select an item you rotate the wheel, and then to confirm that selection you press the center button.
After a few times using it, I actually came to love its simplicity, you could scrub through train stations incredibly quickly, and with just those buttons (and a cancel button) you could complete the whole process of buying a ticket in less than 30 seconds.
Sadly, I think these machines are on the way out.