People love to know about extremes, about record-holders. What's the biggest snake in the world? What's the fastest bird? So it's not surprising that, when you talk about venomous snakes, you get a lot of folks asking, "What is the deadliest?" To which I reply, "The one that bites you."
It's hard to categorize snakes by how dangerous they are, because there are a lot of factors that go into the calculations. Venom is obviously one; some snakes have venom that is extremely lethal to humans, others have something that could technically be called venom, but mostly results in slight itching in people. There are other factors, too, however. How aggressive is the snake? How much venom does it produce? How much does it inject? Does it live in an area where there are actually people to bite? How effective is antivenom? Is there antivenom?
Questions like these are why sea snakes, like those washing up on the California coast, although having some of the most potent venom in the animal kingdom, generally aren't feared that much by herpetologists.
I've never seen two rankings of "deadliest snakes" that are the same. The one I'm summarizing below is from Black Hills Reptile Gardens in South Dakota, home to one of the deadliest collections on earth. I like their rankings because they do take a lot of factors into consideration. To see their actually rankings, click here - otherwise, enjoy the abbreviated Top 12 List below.
12. Papuan Taipan
11. Barba Fer-de-Lance
10. Puff Adder
9. Coastal Taipan
8. Common Fer-de-Lance
7. King Cobra
6. Russell's Viper
5. Black Mamba
3. Mexican West Coast Rattlesnake
2. Saw-Scaled Viper
1. King Brown Snake