I would recommend Train Simulator 2018 which is £24.99 (For PC). Train Sim World  which is £24.99 (For PC) COMING SOON to Xbox One and PS4 – not sure on price. Train Sim: Founders Edition which is £24.99 (For Xbox One). Train sim which is free (For Apple and Android) or Roblox which is free and has a variety of simulators (For PC, Mac, Apple and Android)
Link to Train Simulator 2018
Link to Train Sim
The Xbox One and PS4 announcement
Link to Train Sim World: Founders Edition
Link for Train Sim
Link for Roblox