Oh boy, SO many favorites. Number one in my mind is the original 2001 Jeff Gordon fire and flames scheme. MUCH better than the rainbow. I am also a huge fan of the reverse colors Performance Alliance schemes where the flames were blue and the car was red.
Top ten in no particular order:
2001- Jeff Gordon Dupont 24 Chevy
mid-2000's Jeff Gordon Dupont Performance Alliance Chevy
Darrrell Waltrip Western Auto Chevy
Dale Earnhardt Goodwrench #3
Harry Gant 1982-1983 Skoal Bandit Buick
1982 Ricky Rudd Piedmont Monte Carlo SS
Cale Yarborough late 70's Busch Beer Olds 442
Ryan Blaney 2018 PPG Ford (Heck, I like almost ALL of the Penske cars, but especially Blaney's cars).
Bobby Allison 1972 Coke Machine Monte Carlo
1983-1985 Tim Richmond Old Milwaukee Pontiac.
Honorable mention:
David Pearson Wood Brothers Purolator cars
1982-1985 Bobby Allison Miller Buicks
1986 Tim Richmond Folgers Monte Carlo w/gold foil car numbers
1983-1984 Cale Yarborough Hardees Monte Carlo
Early 2000's DEI cars, I liked all three, and liked that they all had a common design theme. You knew a DEI car when you saw it.
1991-1993 Rusty Wallace MGD Pontiac
1984 Darrelll Waltrip/Neil Bonnett Bud cars with the bowtie shaped Bud emblem on the hood.
Mid 70's James Hylton Nitro 9 cars
Late 70's Richard Childress CRC Chemicals Monte Carlo
I'm sure I'm missing a lot, but it's a start. My favorite race car colors, in fact favorite colors are in order; metallic blue, metallic red, charcoal gray and black. I normally don't like green, yellow and orange, BUT they can be used to great effect on a race car.