Another non-traditional poll, but it's another question that I've been curious about: what crossing lights have you seen, whether on display and/or in use? Gate lights can be included in this as well, along with wig-wags (both kinds). As long as it functions as a visual means of warning drivers, then it counts, as long as you've seen the light(s) yourself in person. So nothing you've seen only on videos, pictures, and/or Google Street View.
Here's my list (ones I haven't seen lit up are marked with an *, any "generations" are named as such by yours truly, and aren't official, except for LEDs as they were named as such by Mike H.; different generations/styles of the same light-head are also linked to example pictures I've taken of the light head):
8 inch lights:
US&S
Safetran
RACO
GRS XC (IIRC, that's the model for the standard GRS 8 inch light)
GRS Lex-C
WCH
WRRS
WRRS Cast-iron*
Federal Signals
WABCO
Harmon
Modern Industries
Transport Products Corp.
12 inch lights:
WCH 1st Generation
WCH 2nd Generation
WCH 3rd Generation
WCH 4th Generation ("flat-back" style)
Federal Signal
GRS Lex-C
Harmon Style 1
Harmon Style 2
Harmon Style 3
Modern Industries 1st Generation
Modern Industries 2nd Generation
Modern Industries 3rd Generation
Safetran
Safetran - Old Design
Safetran - Hawker Siddeley Logo
RACO
RSI
Alstom*
General Signals*
L&W 1st Generation
L&W 2nd Generation
Transport Products Corp. (No Left Turn light)
WABCO/US&S*
US&S
Progress Rail 1st Generation*
Progress Rail 2nd Generation*
8 inch LEDs:
WCH 1st Generation
WCH 2nd Generation
12 inch LEDs:
WCH 1st Generation
WCH 2nd Generation
Leotek EV Series
General Signals
General Signals MAX*
RSI
Harmon Dotted
Harmon Fading
GE Dotted*
GE Uniform Look
Progress Rail*
Dialight Ball
Safetran Fading
Alstom*
Incandescent Gate lights:
RECO
Safetran
WCH
NEG
WRRS Lantern*
WABCO(?)
Progress Rail(?)
General Signals
L&W
LED Gate lights:
RECO
Alstom/Aurora*
Progress Rail(?)
NEG RECO-style
General Signals
RSI STOP*
Dialight*
Misc.:
WRRS Autoflag Wig-wag
Magnetic Flagman Signal Co. Wig-wag*
GRS STOP lights*
US&S STOP Lights
US&S 9 inch Lights
What lights have y'all seen?