Mmm, Metroid Prime. One of my all-time favorites, and yet it's been far too long since I've last played it. For that matter, I don't know that I've ever watched a speedrun of the game in its entirety. This 55:53 single-segment run, performed by T3, is a good one to go with.
There's something extra special about seeing a speedrun of a game you'd normally take your time with as much as possible, and boy did I take my time with Metroid Prime. How could you not? I distinctly recall marveling at how alive, how endless Tallon IV felt back in 2002.
Looking at the game now, it obviously wasn't. But I'll remember it that way. Always.