I have many that I like, quite a few of which have been mentioned earlier in this thread but; I have to reserve the number one slot for the former PRR station in my hometown, Lewistown, PA.
I visit the station each summer when we go back north to visit family and still feel a rush of anticipation when I cross the Juniata River bridge right before reaching the turnoff for the station.
The PRRT&HS restored the station years ago and houses their archives there. Amtrak still stops twice a day and NS adds another 60 or so trains to the mix. It's a great train watching spot and the local rail fans are always friendly to visitors.
i credit this station and my father for developing my life long interest in railroading. Dad would load me in the car after Sunday dinner in the 1950's and we'd go to the station to watch trains and talk. If a railroad station can hold a treasured spot in your heart, Lewistown station holds one in mine.
Curt