As silly as some of the licensed sets are, I like 'em. Peanuts, Polar Express, Harry Potter, NASCAR, etc. And of course I then collect all the add-on cars that go with them.
And all of Macy's thanksgiving boxcars, beer cars, food cars, etc. Mostly Lionel, MTH and K-LINE. And some Atlas and RMT.
And candy cars: just got a Pez Aquarium Car to add to my Tootsie Roll and Lifesaver's train.
