S scale 1:64 - its the perfect size and delightfully idiosyncratic! Cambrian, light railways, industrial, narrow gauge and American shortlines. Also 1:152 2mm Finescale and 2mmNG, and some overseas modelling in 1:160 N scale.
I had a great day demo-ing 2mm scale narrow gauge at NG South West, Shepton Mallet yesterday. Thanks Jerry (queenssquare) for helping out at such short notice - I owe you a pint!