I tend to look at popular titles with plenty of sequels just to see how they evolve.

For Metroid I already watched a playthrough of Metroid, Return of Samus on GameBoy color, Super Metroid and Metroid Fusion. The last one was a step up from even Super Metroid thanks to having a unusually well written story for these kind of games. I have Metroid Prime 1-2 om the GameCube so I might try those later. Now Metroid Zero