Now you've gone and done it!
Back in the day when I lived on base and outdoor antenna's were not allowed, I had to funnel my energies elswhere and model railroading was it. Didn't help that a civilian friend of mine had an entire basement of HO.
I was into "N" due to size restrictions. My older brother (also a ham) was into "O" and had a nice Lionel set, the Texas Special.
Two gauges that has always intrigued me are "Z" and "S". There is some nice stuff avaiable in Z, but S never really took hold and finding stock, track, and accessories for it is a task.