For a nice simple train game that isn't really technical or complex I enjoy "Sid Meier's Railroads!"

It's like an arcade tycoon game. Pick an area and you can randomize the geography or use somewhat real life. You can grow cities by supplying products to them. And you'll have rival companies trying the same, you can buy them out if you're doing very well. It's a nice lite game I used to play while listening to podcasts.