It's not the End of the World.. or is it?

I was browsing TV channels today when I saw that Independence Day was running on Star Movies. If my dad did not want the remote and if my brother didn't have exams, I might just have sat down and given it a watch. There's something about Doomsday movies isn't there... even to a skeptic like me. Because being skeptical is one thing; crossing the fine line separating it from blissful obliviousness is another.
And as easy as it is to believe that the Earth is invincible, that we've been around for billions of years and we can do another million just fine, that the Y2K, 2012, Roswell theories are all merely conspiracy theories writers and movie makers thrive on, there's still the nagging feeling of is anything permanent?
Everything has to end right? Can immortality stretch to encompass the non-abstract? Okay, that sentence sounded a bit pompous, but what I'm trying to say is how much sense does it make to keep believing that our world is forever?
So let's say the Earth, like you and me has it's expiry date. Then there has to be a perpetrator . What are the possibilities...

a) Environmental Disaster?
Lets face it. This does seem the most likely at the rate we're disposing/deforesting/procreating.
Movie equivalent: 2012, Day after Tomorrow

b) Meteor Impact
I read in a NASA article that this did cause the extinction of Dinosaurs (am i wrong to be relieved?) So it can very well happen again, it's been a few million years.. Maybe it won't even be a planetary annihilation.. maybe humans will disappear like the dinasaurs. I just cowardly hope that I'm at the focus of impact so I don't have to see anything.
Movie Equivalent: Armageddon

c) Microbial Epidemic
SARS, Bird Flu, Swine Flu.. We've all seen it happen. No reason why it shouldn't happen on a larger scale. I'm a little skeptical about Cannibalism however.
Movie Equivalent: 28 days later,Dawn of the Dead, The Happening etc..
Book Equivalent: Cell - Stephen King

d) Extraterrestial Invasion
Science states the existence of millions of galaxies in the Universe. Meaning gazillions of planets. The chances of Earth being the only one with life are negligible. There has got to be another 10000 planets at least with intelligent life on it. Let's just hope they're friendly..
Movie Equivalent: Independence Day, War of the Worlds

So that's all I came up with. I don't mean to be morbid I swear; I'm just naturally a little unhealthy in my thinking. If my writing was so powerful that it's scared any of you, don't be. Read this interview with a NASA scientist. I dare say he knows more..

http://www.nasa.gov/topics/earth/features/2012.html

Happy Weekend!