I like the one at the end of Super. Fusion's isn't too bad.
Idk how old I was when I first played ZM, but I know I was completely ignorant as to what sequence breaking and speedrunning were. The whole lose ur suit at the end came as a surprise to me, mostly just because I totally thought I beat the game and was waiting for the credits to roll the first time I made it there haha. When I play the game now though it almost seems like a nuisance when I get to that part and my "gaming gusto" starts to dwindle... Still one of my top 3 favorite metroids along with the first and second Primes.