Scotch or Bourbon on the rocks is the best drink.
However, for drinks/shots one of my favorites is:
Makes 1 shot
1/2 ounce Jagermeister
1/2 ounce peach schnapps
1 1/2 ounces cranberry juice
Instructions: Mix ingredients in a cocktail shaker with ice. Shake well, and strain into shot glass.
*This can easily be re-proportioned to be a drink instead of a shot. Just pour the shaker into drink glasses. It's actually quite tasty (even the ladies like it)
Another pretty fun drink (not so sure how playa friendly it would be, although Guiness is always good warm, and it's a straight shooter, not sure if you are looking for drinks or shots, is an Irish Car Bomb
It's just a glass filled 1/2 to 3/4 of the way with Guiness and then a shotglass with 1/2 Baileys, 1/2 Irish Wiskey. Drop the shot in, and taste a glorious experiment in flavor mixing. It's quite tasty, sort of coffee like. This CANNOT be drank in any other method than as a shot, the baileys curdles when it hits the beer. Baileys would also be a pretty bad thing after a few days on the playa, so it would have to be a "special treat" type thing. Something for either the first or second day, or something someone who was coming in late brought in.
Hope this helps, or give you anything new. I'll have to stop by and have a RHS!