What is your favorite aspect of model railroading?

[ezdays]

There are some things I like to do and other things I just find difficult to tackle on my layout. Here is where you can list the things that make your modeling a pleasure to do. Feel free to post the one thing that you like best to do, or even a couple of things if you can't choose just one. There is another thread that I've started to post the things you like the least to do on your model railroad.