It depends on what YOU like? And what you want to do with the "set" the rest of the year? If you like the traditional toy theme, and scale realism is unimportant, Marx is inexpensive and abundant; if your theme is nostalgia, Standard Gauge. If the set is to be the basis for expansion into a year around layout, l would pick an all- purpose ten-wheeler or F unit , freight cars, and a lighted combine coach on the end, to cover all the bases. That if you want most bang for the buck not constrained by season.
