My two favorite versions are by Nat King Cole, and the Bing Crosby and the Andrews Sisters version both versions made shortly after the song was written. Both versions have that 40's wartime feel but sung in 1946 they also have that great feel of post-war optimism. But there have been some other great versions of the song made and still being made. Visit Wikipedia or Route 66 Magazine for a list of the artist and bands that have remade the song.
If you don't know the story behind the song here it is. The War (WWII) was over and Bobby Troop and his wife where traveling west. They came from Pennsylvania to Chicago to catch Route 66. To say the least they where enjoying Route 66 so much Bobby decided he wanted to write a song about it to get people to drive the route and have the same great experiences. The only problem was he just couldn't get the song put together in his head. He knew he wanted city names in the song, but the chorus was killing him. Finally as legend has it they where outside of Tucumcari, NM when his wife blurted out the phrase "Get you kicks of Route 66!". To say the least the song came together at that point, and by the time they got to LA the song was written. Inspired by and born on Route 66.
Driving down Route 66 now its hard to not want to pop the song on. It's also hard to not see the song eluded to just about everywhere you go down the route.
Traveling with your family you may find the song is great for introducing your kids to the route, and teaching them a little bit of geography too. The song can help them learn cities and even states along the route. Give your kids a map and they may be able to show you the way down Route 66 just by singing along and pointing out the town the song names.