A massive alien ship/space station hybrid, built to lay siege on entire planets, makes landfall on Earth, somewhere desolate and remote to minimize the damage it'll cause when it blows up (spoiler alert: this fantasy ends with me blowing up the invading alien space station, I know you're all shocked). All of this is actually the work of a single alien individual, who invested his every resource into creating the (completely automated; he's offworld) siege craft and filling it with an army of robots whose directive is to exterminate all of humankind and wipe Earth clean of all traces of them so that their master can take possession of the planet and legally sell it, what with there being galactic laws against taking ownership of planets with a sentient native population... plus, you know, xenocide. My conscience thus clean of any remorse that might come with having to kill any sentient lifeforms (alien invasion or not), and with the fate of Earth - and an untold number of other populated planets that will suffer its same fate - on my shoulders since the station is impervious to even the heaviest of the various nations' weapons fire, I persuade the government to give me some weapons and ammo so I can infiltrate the craft (don't ask how, or why they wouldn't just send in actual soldiers for the job), as well as set me up with a video feed for them to watch (and record, naturally) and a high-volume speaker to hang on my belt.
Before I go, I record a private speech, to be released posthumously, in which I explain my certainty of my own success thanks to God appearing before me and everything, as well as the instruction and enrichment that a life of playing video games has provided. Also, I get the chance to meet and thank a few personal heroes like J.K. Rowling, Lauren Faust, the RedLetterMedia team, Yahtzee and Jim, etc., and of course give my final goodbyes to my family and friends in which I take careful note to explain that this is an unequivocally happy thing and they should look forward to the day when we get to see each other again rather than mourn me.
I travel to and successfully infiltrate the alien station, and manage to reach the control room undetected. At last, I unholster one of my weapons and start blasting away at the robots occupying the room. Several of them get the chance to draw their own weapons and fight back, but I manage not to get hit, and finish them off. With the room clear, I go to the control console and activate the self-destruct sequence (as opposed to overloading the reactors, so that the alien criminal responsible for the invasion will have to live with the knowledge that the ruining of his livelihood could have been avoided if he hadn't equipped the craft with a self-destruct sequence). I spend the minutes it takes for the timer to run down - long enough for me to get as much enjoyment as possible out of fighting alien robots, but short enough that it doesn't lose its appeal or wear me out physically - holding the control room against the hordes of robots trying to get in and cancel the self-destruct sequence, eventually using up all of my weapons' ammo and taking up the robots' energy weapons instead. Also, this whole time that speaker on my belt is blaring a soundtrack composed of the likes of "Welcome to the Jungle," "Kickstart my Heart," and "Metal Machine" as well as the occasional divergence like the climactic music from Meet the Medic [http://www.youtube.com/watch?v=-6NQx4WRRg0]. My last challenge before the timer runs out is a giant robot that I manage to climb up and kill by firing a rapid succession of shots into its neck joint and mouth. I die laughing with childlike glee.
As a result of this feat, I go down in history (aided by the recorded footage) as a great hero, and the influence of my status combined with the release of my prerecorded speech leads to a wave of worldwide spiritual enlightenment and the complete eradication of all remaining social stigma against video games, which are in fact subsequently propelled to the status of the most popular and revered artistic medium of them all. Robbed of his one source of wealth, the alien criminal is swiftly captured by the galactic authorities, and the matter brings their attention to Earth, which is quickly offered a place in the utopian galactic civilization. Everything is perfect for the rest of forever, the end.
...On a totally-unrelated-no-really-I-swear note, I just got an idea for a novel for which I need to go brainstorm.
