I run 1:16th scale locomotives, mostly narrow gauge style locos, Although I have aquired quite alot of american-esque rolling stock, so it could lead me to buying a D&RG Sandy River
My dad and I do the occational bit in the bigger stuff, Here's an 0-4-0 electric chassis we started a while back to run on either 5 inch or 7 1/4 gauge track, just never got round to completing it.
It needs a good clean up, and a set of dummy axle boxes to go on the side.
I have also had N gauge, and HO gauge layouts, but I got rid of them, for the larger stuff.