The best is classic Pullman green
The green red and cream of Pennsy's "Yellow Kid" scheme was pretty great too.
For me it boils down to these two
Delaware and Hudson Blue, Yellow, and Silver ( got to love those PA diesels :-)
B&O Blue and Gray
Happy Railroading
Patrick W
The Free State Junction Railway " Where the trains always run on time "
Southern Pacific Daylight (dubbed the most beautiful train in the world).
Jersey Blue Comet
Milwaukee Road Hiawatha
Being a Southern girl, it's got to be green. 
But my next choice can only be Milwaukee maroon & orange. 
I don't have a favorite; but, this seems fairly impressive -
http://www.youtube.com/watch?v=WVZdQuPh4WY
Rick
http://www.youtube.com/watch?v=8AEykp3Itbk
Check out the odd looking locomotive, at the rear of the new Talgo train. Amtrak's Talgo colors grew on me, after awhile. I often see Amtrak's older Talgo coming and going... in the metro Vancouver area.
Rick
ACL-purple
Probably the Daylight....BUT...I love just about any passenger train in whatever color!!
Alan
As a child of the Amtrak era I never got to see much (any) old school passenger rail, which is likely why it doesn't feature prominently in my collection. However, I have both the Lionel Chessie Steam Special trains--the so-so version from the early eighties and the nicer one from 2005. Love those colors!
Any passenger train is okay with me! 
1: PRR Tuscan red
2: B&O Blue/gray
Originally Posted by Hot Water:
Originally Posted by Number 90:
Unpainted stainless steel with silver trucks, of course.
Agreed! Anything Santa Fe, besides that's the train I took in order to come and go to College, The Texas Chief. Definitely FIRST CLASS!
+1 more for stainless.
All the Burlington Zephyrs were also Stainless. And the Seaboard Silver Meteor, PRR Congressional, streamlined Southern Crescent and Sunset limited, etc.
#2 for me would be Pullman TTG. Very classically understated.
What I have dared not state, as it is posted as a favorite above, is my most disliked
passenger colors
......I am looking at a photo of the 1939 D&RGW Exposition Flyer in
B&W. What I have not seen is D&RGW heavyweight photos in color (this is pre "Bumble
bee" silver and orange). I presume some shade of Pullman green, but have not seen those in color nor any commecial models of them.
