* Dasher
* Dancer
* Prancer
* Vixen
* Comet
* Cupid
* Donner
* Blitzen
This order comes from the 1823 poem "A Visit from St. Nicholas" (aka "Twas the Night Before Christmas") by Clement C. Moore.
While it's likely that Santa arranges his reindeer based on their specific talents and strengths, the poem gives us the most common and accepted order.