[Sam Hill]

Don't worry the quantum formation of your brain means you will survive until you reach the maximum statistical probility of surival available in the current universe. This means whatever you do you will never be in situation where this arrises. But you have died numerous times already ,so don't worry about it, your used to it. And at the momment that age is about 130.

[Keebler Elf]

Personally, I believe that t North Africa also known as the Sahara Desert would be the ideal place for an asteroid of this hypothetical magnitude to hit earth. Antarctica would be a very bad idea. This is because if an impact were to take place there, trillions of metric tons of ice would be instantly vaporized, in turn causing the formation of storms of epic proportions, all the while the rest of melted ice would create tsunamis of their own. This is due to the amount of water that would be released by Antarctica’s melted ice sheets into the oceans (About 2.0% of Earth’s water is frozen down there or 70% of all the fresh water on Earth). The ideal place would have to be a low populated area that is dry.
On a further note…
 And since no one has mentioned it as of yet. I was thinking that mountains might be a good place for an asteroid to hit not only because they are lowly populated but also because of their high elevation (Let’s just say, in the middle of the Himalayas). This could perhaps allow debris to be thrown far enough pass our atmosphere where it would not be pulled back in by Earth's gravity (Less distance for the debris to reach space). This would cause less heat by the debris re-entry into Earth’s upper atmosphere.  All this debris would be the equivalent of billions of small asteroids hitting the Earth all at the same time inevitably causing Earth’s overall atmospheric temperature to increase, creating an “oven effect”. Though if blasted far enough and with the help of higher elevation this would cause less of an “oven effect” while also causing less future acid rain AND since this is a hypothetical perhaps some of the debris blasted up by the asteroid  that went far and fast enough created a small ring that orbits Earth.  (Like a smaller version of Saturn’s rings) At least it would give the Moon some company…  

[Keebler Elf]

Sorry, I did not mean to double post just then! I started registering in the middle of writing the above response...

Probably not the best circmstance to introduce myself but what the heck...  []

Well, hey everyone I look forward to meeting with you all! Just call me Keebs...

[litespeed]

There is no safe place for the asteroid. It would suffer roughly the same demise where ever the impact.

[Charlotte]

It's ridiculous to speculate. (1) We don't know where it will hit (2) That large, it will destroy everything while blocking the sun with debris.

[Menno]

No matter where it hits it is bad for everyone but if it hit where are the best places to live? I'm up in the rocky mountains good or bad?

[Tyro Abecedarian]

Antarctica has a lot of nasty issues as well, the vapourisation of billions of tonnes of ice, the fracturing of the rest of the ice would lead to a potentially large scale shedding of the glaciers. The steam and water clouds released from that alone would create a barrier to the sunlight for years, potentially leading to a mini ice age. however, should the impact be just right, it could trigger a volcanic event opening a chain of Volcanoes radiating from Mt. Erebus. The resulting super volcano would likely melt the remaining ice sheets and either way, a very sudden and lethal global flood. Add to that the usual fallout from large scale vulcanism. earthquakes, potentially unzipping the pacific ring of fire if the tectonic forces combine. Toxic gasses, a climate that would block the sun and...well, let's just say it would be a pretty bad day for us all. I dare say even the cockroaches wouldn't be doing exceptionally well