My favorite car is one that carries high wide loads - large flats and schnabel cars. Here are a couple of ones that I am working on.
GEX 800003 - 20 axle depressed center flat
WECX 200 -12 axle schnabel car with transformer load
WECX 301 - 22 axle schanbel car with nuclear reactor load
Still need get better at using my air brush before I tackle these.
I have 9 schnabel cars and 4 depressed flats over 100 scale feet long in my high wide fleet.
More one these large cars on my website -
Tom's Trains Pages
Tom