I joined the O gauge/scale world in 1997. My parent moved from their house to florida and anything in their Chicago house ended up in my house. HO stuff arrived, most importantly the benchwork. I built my layout and then kind of went crazy, with ebay, etc.
My first engine was a GP9 Santa Fe, TMCC ready engine. This opened the door to Santa Fe, and BNSF and of course backwards to Burlington and Burlington Northern.
At first I collected the 6464 cars. Bought pretty much all the remakes and then several older cars. Really liked those. Subsequently sold 100%.
Growing up in Ohio, I figured I should model B&O, C&O and any successor railroads, welcome Conrail, CSX and Norfolk Southern. I also went backwards from there and picked up some Southern and Norfolk Western.
I got into NYC as my son is from there, so now have a roster of steam and diesel which also then can tie to Conrail and NS.
Finally I love some of the Southern Pacific engines, daylight, black widow and the great looking grey.
As I wrote this I realize I need to purge some engines. Maybe a different topic on that from me.