From: Metal Gear Solid
As evil clones go, the ones that threaten the world with thermonuclear war and eradication rank as some of the worst. Don’t let the confusing minutiae of which organization sent Who to kill Whom distract you. Dig deep into the squirming, pulsing, fluid-spouting, piping-hot core of Metal Gear Solid, and you’ll find a simple narrative thread: your twin brothers got into Dad’s drawer, found his loaded .45, and they’re waving it around the house with the safety turned off.
Forget the Batman villains. Forget the Do-Re-Mi-Fa-So-La-Di-Do. Forget the unsubtle references to colonoscopy and Titanic. Just focus on how awful Liquid and Solidus are. Liquid (and his apparent crony Ocelot) gave you carpal tunnel from jamming on the Circle button long before you ever got near a desk job. Solidus is the core participant in a video game trolling that still has yet to be surpassed after a decade.
And if you’re British, we hope you can appreciate that while you had to deal with yet another “we’re the villians” trope in MGS, having your elected leader be the jerk who tries to destroy your homeland is arguably worse. Especially after you’ve had to give a giant tank a proctology exam. These are horrible, horrible people, and they came from the same petri dish as Snake.
From: The Legend of Zelda series
First appearing as the final boss in Zelda II, Dark Link (or Shadow Link, as he was originally introduced) is the quintessential dark clone distilled to its purist form. We tend to take for granted that Link has the ability to eventually subdue the ever reappearing evildoer Ganon – the hero always wins, after all – but Dark Link is a different kind of enemy. He's undeniably Link's true equal, perfectly matched and mirrored in every way.
Even with a ridiculously exploitable weakness in Zelda II (he's totally vulnerable whilst jumping), Dark Link has gone on to appear multiple times within the Zelda series and has become a huge fan-favorite as a recurring enemy. Most famously, his appearance as miniboss in the Water Temple of Ocarina of Time is memorable as a particularly tough fight within a notoriously difficult dungeon.
As the genesis for the dark counterpart archetype in gaming, Dark Link also inspired NegaScott from the Scott Pilgrim series, which highlights the psychological aspect of confronting your evil self. Indeed, Dark Link serves as a reminder not just to Scott Pilgrim but to all videogame lovers that even the most noble and courageous among us still has a shadow lurking somewhere within.