@Markus - I have to disagree with you about the gaboon viper. The Eastern Diamondback Rattlesnake is actually bigger than the gaboon. The largest one ever captured weighed in at thirty four pounds and was nearly eight feet long.
They too are extremely venomous and are responsible for most human deaths caused by snake bites in the United States. The Eastern Diamondback Rattler is a pit viper located in Florida. It searches for its prey from heat receptors that are below the head.
The Eastern Coral Snake, also in Florida, is the most venomous snake in North America and the Mojave Desert viper snake in California and Arizona is the most venomous rattlesnake in the world. But I do agree with you that the gaboon viper has the longest fangs than any other viper snake.