If there was ever a video game franchise that demanded a listing and ranking of its numerous and iconic boss battles, it is without a doubt Metal Gear Solid. These unforgettable characters are the only personalities more bizarre and idiosyncratic than series creator Hideo Kojima himself. Despite all of the lunacy, the franchise has also managed to keep one foot grounded in reality to simultaneously tell quite arguably the most riveting overarching story in all of gaming. And while Solid Snake/Big Boss are typically the stars of the games, heroes are only as compelling as their villains. Kojima is clearly aware of this belief, as across four canonical games he has blessed gamers with a host of unique villains along with wildly unconventional fights to heighten the memories. Boss battles aren't just treated as punching bags to further the story, but rather an extension of the story and an opportunity to pull off some drastically unique gameplay moments. This is a franchise whose most iconic boss fight - possibly even its best - forced players to plug their controller cables into slot two as an act of avoiding having their actions read by a psychic character. On the surface level that's awesome, but it's also a decision that wholeheartedly takes advantage of the interactivity aspect of video games, the very thing that sets it apart from every other entertainment medium. Truthfully, these boss battles are so unique and multi-layered that roughly half of this list could be a viable option for number one. With that said, a lot has been accounted for when putting this ranking together; it's not just singularly about fights that paved the way for emotional story beats, exhilarating and intense gameplay design, the characters themselves, or the fact that these fights become even more complex on higher difficulties - it's a combination of all these boss battle factors weighed and balanced against each other.