Super Metroid. The most important thing about Super Metroid is the complexity of it's platforming and the way it weaved that into the exploration. The way it used platforming as a way to make the player feel like a superhero, and the interesting ways it was able to create ambiance and tension exclusively with those mechanics is something the series has never seen since.
Moments like fighting the behemoth Kraid by jumping between giant spike he shot from his stomach are completely without replication without that level of platforming. The claustrophobia felt fighting Ridley is completely evaporated without the wider context of a typically agile Samus.
I obviously say this because the Prime games are the only real competition. Metroid is a lesser franchise without that integral part of its DNA, and even though Prime is an excellent game, it is no exception to this.
Other M isn't work mentioning, Fusion was linear and had a narrative as bad as Other M, and Zero Mission was stained with the introduction of the Zero Suit, and was the genesis of the downward spiral of the character of Samus Aran. Also it shoehorned in the shitty Prime-style orchastral/choir sound fonts for no reason. Ew.







