My boys came to me with the names Mr. Blue and Clint. No, no, that will not do. So I made a list of classic duos:

Butch Cassidy and Sundance
*Captain America and Billy
*Jake and Elwood
Connor and Murphy
Bo and Luke Duke
Scooby and Shaggy
*Bill and Ted
Ron Burgandy and Brick Tamlan
Wayne and Garth
Newman and Redford
Turk and JD
John and Steve
Fact and Fiction
Spam and Eggs
Napolean and Pedro
Wolverine and Sabertooth
*Mal and Jayne

*Names I was partial to

But Captain America and Billy won out, partly because of the obscurity of the reference (the two main characters in Easy Rider [1969] starring Peter Fonda and Dennis Hopper) and partly because their personalities matched.