The Harlem Line add-on in Train Sim World offers high-density commuter services out of the iconic Grand Central Terminal, but only up to North White Plains, so the route is a measly 24 miles long.

It does include a decently-busy timetable two distinctly different electric trains, namely the Metro-North M3A and M7A, but there are so many problems with this add-on (apart from just the stupidly short route coverage) that I can't recommend it to anyone.