Well I have alot of experiences with the Virgo people and my main dark side against them is because of their fussy and picky, also perfectism which are very annoying to me, no offense to the Virgoians. My two twin cousins are Virgoian, and they always act like they know better and can do anything better than anyone other than them, they just kept acting like they are perfect. Their obessive about being perfect and have things that are perfect
do drive me crazy.
Those are just my expression about dealing with Virgo, but oddly, when we chat, I get along with Virgo so much better because they are very honestly people. Also they are pretty caring people, would willing to help other people to be perfect, but sometimes it's thing that I don't want.
But Virgo is not the only one that I have so much opposite, I do have alot of opposite from Taurus, Scorpio, Cancer, Aries, etc. But I don't have much thing that I do not along with Libra, Gemini, and Aquarius.
It's because Virgo have the element that are different than mine. Let me give you a guide:
Fire: Aries, Leo, Sagittarius
Earth: Virgo, Taurus, Capicorn
Air: Aquarius, Gemini, Libra
Water: Cancer, Scorpio, Pisces
Fire, Earth, Air, and Water are the elements, if they mix with different elements, there are more chance that they will not get along than if they mix the same elements.
It's just my opinion
Also that's what I learn from the Astrology Bible, and I find this guide very helpfully.