There are 26 letters in the alphabet. 25 would have been a much nicer, round number. But they put "X" near the end instead. In my mind there is no instance where the rare usage of the letter "X" couldn't be replaced with other letters to make the same phonetic sound. "X" is just there because it's awesome. It's exciting, exuberant, exsanguinous too i'm sure. Slip an "X" into a word and it's instantly better for it.
Got some men with superpowers? BAM! They're the X-Men. Are your games just that much more awesome than regular games? SHAZAM! They're X-Games. Got a ray that can look through your body and see your freakin' bones? Calling it Eks-Ray ain't gonna cut it. It's a freakin' X-Ray. "X" means treasure. 3 "X"s means porn. Whenever you use an X, awesome sauce is guaranteed.
The letter "X" looks like a guy standing legs apart, arms open wide, saying "Yeeeees!" Granted, this guy has no head, but it probably got blown off from the sheer awesomeness of his body forming an "X". X is worth 8 points in Scrabble. If you get it on a triple letter score, and get a triple word score somewhere else in the same word, you're winning more than Charlie Sheen (topical reference FTW). True, Z and Q get more points, but that's because they're awkward and cumbersome.
If you're doing algebra, you're probably trying to find "X", 'cause "X" is elusive, and is a symbol for the unknown. Once you find out what "X" is, you're awesome, and anytime you use a word that contains the letter "X" in conversation you will instantly have people's attention. That's why not many words have a letter "X". It has to be used sparingly in case you make everyone's face explode from using it too much. See, eXplosion. You can't avoid it. You can have too much of a good thing.
This quixotic review has reached its apex. I must exit due to exaggerated excitement, but expect to receive an influx of sexy minxes coaxing me into XXX rated exploits. Sorry, I may have just exploded your face.