I got into model railroading because of my Dad.  I inherited a few classic trains after his passing, including a 1937 Lionel 1668E, a 1947 Lionel 221W set, and an AC Gilbert Hudson set (HO), along with a few other locos, cars, and accessories.  I collect mostly O-Scale (95% Lionel), but also have HO, S, N, and Z-scale.  Most of my O-Scale consists of Disney trains and accessories.  Every other year, I set up a Disney World display, with monorails and an HO train running around the Magic Kingdom.  The Z-Scale substitutes for Big Thunder Mountain RR, and runs on a model that my wife & I collaborated on.  The layout itself is on a 22x8 platform.  In alternating years, I set up trains pretty much everywhere around the house, including 3 around one tree, and 1 each around our two small 4-foot trees.  Bottom line:  I'll have 18 trains running on temporary displays:  G, O, S, HO, On3, N, and Z.  I'm hoping to find a place when I retire where I can set up a permanent display. My next venture:  a Kato SP GS-4 N-Scale DCC set, if the wife lets me.