What Makes Metroid a Masterpiece?

We love Metroid here at Latest Game Reviews, so we are always looking for stuff about our favorite intergalactic bounty hunter, Samus Aran. This Video from ITOI- What Makes Metroid a Masterpiece is a fun insight into the first Metroid game. I understand why some folks prefer Zero Mission over the original, but the original NES Metroid is a true masterpiece. I love the remake, and the quality of life improvements make a world of difference. 

I enjoyed this video, and I never thought about the Alien inspiration before. I hope you enjoy it too. The Metroid series is still one of my favorite games today. What is your favorite Metroid game?