Its super hard to choose just one snake, so here are my votes

Non-venomous

Rhino Ratsnakes
http://www.proexotics.com/collection...ids_rhino.html
Red mountain racers
http://www.proexotics.com/collection...rids_coxi.html
Boelens Pythons
http://www.proexotics.com/retail_pro..._1-25-02_5.jpg

Venomous
Gaboon Vipers
Aruba island rattlesnake
http://homepage.mac.com/wildlifeweb/...ttlesnake.html
Sumatran Pit Viper
http://www.naturemalaysia.com/sumatranviper.htm