In 1997, I bought my first house. One weekend while shopping around for furnishings, I happened across a knick-knack shop which had among other things, the Tyco Lambourghini Challenge - for $30.00. All the bridge pieces, the pwr and controllers, two cars, and 64 ft of track. I built up a table for it in my garage, and while shopping for more track one day, I happened across two of the HO scale-electrically functional railroad intersections, which started a monster. I started buying up all the HO scale train track I could get my hands on, and built up a huge diorama-esque train-race track set, which the race track and train track intersected and winded thru itself, and occasionally, when friends were over (during paties and whatnot), we'd do the Addams family thing, where if you timed it right, you could crash the cars into the oncoming trains.
I've since moved, and have all that stuff stored in boxes now. When my fiance and I get hitched and get a home of our own, I plan on reconstructing the monster even bigger than before.
Man that was fun...