SkipMagic would be a Jack Chick tract promoter who actively shuns any real life encounters with fellow Mirror Universe Dopers. His posts betray a total lack of understanging of classic literature or contemporary music. He also seems to be living in a run down flat in the warehouse district of Los Angelas.
Or a really offensive, stubborn Fundie desperately trying to prove his faith by threatening everyone with hellfire.
NoClueBoy would, in fact, have a clue about everything…except Star Trek. 
Scylla would be a gun-control freak who keeps pet groundhogs and can’t tell a joke without starting with the punchline.
Orbifold would be a math-phobic twit who only hangs out at the boards to commiserate with Chronos and DrMatrix about how much all these smarty-pants who understand fractions suck.
Lekatt would…
nah. Too easy.
The Bad Astronomer would work at the mall in a specialty shoe store catering to the obese woman. He would argue til blue in the face that the moon landings were all a hoax and have many many documents to prove it. He just can’t get to them right now because the Government is watching him.
Coldfire and I would still be fanatical devotees of RUSH
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wait for it…
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RUSH the blowhard radio talk show host!
::Sniff:: My mirror self loves you.
yosemitebabe is the driving force behind the politcal effort to invade Yosemite Park and drain it of all its natural resources. She wants to shoot the bears, convert all of the giant sequoias into Texas-sized toothpicks, and cram Yosemite Valley with a landfill.
Also, she despises Macintoshes so much that she uses an Etch-A-Sketch for her computing and artistic needs.
december would be a sixteen-year-old Muslem girl living in San Francisco, CA. Her posts are deeply insightful, well-argued, and are a constant source of joy in Great Debates. She would insist on using factual cites for every position, and look down on those who quote blogs or editorials to slant a topic.
(Yeah, I know, completely implausible, but hey 
)
Wouldn’t she just be an accountant instead?
Wildest Bill would still be here as the moderate member of the board fair and modest with an open mind to evrery oppinion.
His4Ever would be an atheist and anti Chick all the way.
All the doperettes would be lined up at Mirror Max Carnage’s door waiting for a turn on the Wild Carnage!
** lieu ** would only post about his Junior League luncheons and elegant tea parties and sniff with disdain at those gauche enough to post about any bodily function more offensive than a polite cough.
Diane would politely nag him for his recipe for cucumber sandwiches
Biggirl would be a shy, retiring, humorless prig.
Aw dang it… I’m curious to know if anyone has any oppinion on me and what they think my opposite would be like…
I’ve been waiting for someone to describe mirror-me too, kingpengvin. Guess we’d both be wildly popular in the Mirror Universe, eh?
Oh, yeah, forgot one : SPOOFE would be a diehard Trekkie and Voyager apologist who trolled in every single Star Wars thread he ever ran across.
SPOOFE would also occasionally pop in threads to yell “Overcoats!”
CrankyAsAnOldMan would keep her house heated Farenheit 451 style and would have frequent typos due to drool.
Bippy the Beardless would often disappear on shaving breaks.
Stoid would be pen pals with Dick Cheney and DDG would answer everything with “That’s what you think.”
DDG would also thing “google” was something you did with mouthwash. 
kingpengvin, I don’t know about you, but I don’t know if anyone here retains enough of an impression of me to come up with an opposite. People will at least remember Aesiron from the Star Trek threads.
Eutychus would post complete song lyrics.
Ack. “thing”->“think”. Perhaps Mirror-Balance would remember to preview his posts…
I don’t know you all that well Balance but I’ll take a shot at it:
Mirror Balance would be an ardent technophobe with no use for SF/fantasy or cinema.
How’s that?
dantheman would be a twenty-five year old mallrat from New Jersey named Brenda. Most of her posts would consist of questions like “My boyfriend Snake sells pieces of other people’s cars, and what’s so wrong about that, anyway?” and threads such as the immortal “TMI! This itch won’t go away, and now I’m oozing pus…”
.:Nichol:.
That’ll do, Bunny, that’ll do.
Lynn Bodoni would be out of the hospital .