Southern Pacific Black Widow #1, a close second is the many times mentioned B&O.
NYC's lightning stripes, CNR's green&gold, and also their green/gold/black, Erie's yellow on black, Wabash blue/grey/white, Santa Fe's Warbonnet, B&M's gold-on-maroon, DL&W's maroon-on-grey, and probably many more. Most of the ones I've mentioned are right out of EMD's catalogue on paint schemes.
Many of these, where applicable, looked even better on E-units and Alco cab units often improved on things even more.
Wayne
I'm going to show a bit of national pride here. My favourite F series livery is Canadian Pacific's maroon and grey, with either block or script lettering. The colours are not paticularly flashy but I like them none the less.
My second favourite is Canadian National's green and gold, although I don't own anything (yet anyhow) in CN's earlier colours.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
For me it has always been the Rio Grande Zephyr single stripe Grande gold/silver scheme.
Rio Grande. The Action Road - Focus 1977-1983
While I'm partial to the NYC lightning stripe, the Sante Fe warbonnet is a classic and eye-catching design. And another vote for the B&O, as well.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Thinkin' on that question gets me, well, thinkin'.
There's at least 3 different types of F unit paint schemes.
The first and basic one is the "safe" one. I guess it's pretty much what EMD thought was flashy. It consists of 2, maybe 3 colors running down the sides. They're separated by 1-2 inch strips. The striping sorta "resolves" on the nose. Examples are the B&O mentioned above, GN, SP Daylight. ALL are very attractive. In fact, it's tough to do that ugly-ly. I think. But like I said, it's safe.
There's another type of attractive scheme. I guess it's the "daring" one. SP's Black Widow comes to mind. So does the NYC Lightning Stripes. And NP's Loewy Two Tone.
And then there's just the uglies. The uglies are usually just one color with the railroad name lettered on the side. If there's a logo, it's typically uninspired. Let's not dwell on them.
But I do find it interesting that I somehow came up with the first two groups.
Ed
ATLANTIC CENTRAL The B&O blue/grey/black and gold.
The B&O blue/grey/black and gold.
I'll second that!
Gotta be the ATSF "Warbonnet"!
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
I was going back in some old threads and I found an interesting one from 2007. So what is your F Unit paint scheme? My favorite is Northern Pacific's freight scheme.