by Angelus897
My favorite would be the F units A-B-B-A sets (Santa Fe livery), the Deutsche Bundesbahn's V200, and the original TGV Sud-Est in orange livery.
My current favorites.
Steam:
NYC 4-8-2 Mohawk; cluttered, but well proportioned and powerful looking
Diesel:
EMD SD40-2 with a short nose; the big "porches" give it a fast, better proportioned, more stable appearance than other diesels where the hoods extend past the trucks (see the last generation of Geeps)
Electric:
MILW "Little Joe"; nicely shaped body, massive trucks look powerful