Someone at Urban Dictionary shares your sentiments.
the most overused word ever, next to fail. for even more asshole points, use them together to form "epic fail."
everything is epic now. epic car. epic haircut. epic movie. epic album. epic shut the fuck up.
saying "epic win" doesn't make you sound any better, either. and for fucks sake, don't ever say it in person. DUDE UR POSTCOUNT IZ EPIC FAIL FAGOT
LOL EPIC WIN U RUEL
LISTEN TO THIS SONG IT'S SO EPIC
I also agree with Graham.
To put it simply, the slang usage of epic is so far overused it's sickening. I agree with you.
Google defines epic as "impressive"!
The real meaning of epic as an adjective is much more than just "good".
1. noting or pertaining to a long poetic composition, usually centered upon a hero, in which a series of great achievements or events is narrated in elevated style: Homer's Iliad is an epic poem. 2. resembling or suggesting such poetry: an epic novel on the founding of the country. 3. heroic; majestic; impressively great: the epic events of the war. 4. of unusually great size or extent: a crime wave of epic proportions.
Like Zega said it will die off eventually, in years when all those noobs get lives and when the internet trends change. I agree with the OP, but I don't really mind this, even if it irritates me.