I've sung the game's praises like a bluebird
many,
many times on RGT, but I suppose it's worth reiterating here that
Zelda 2: The Adventure of Link is my favourite one. It's challenging and mysterious, but rewarding and exciting in equal measure, and I truly do adore the game's sense of progression and atmosphere. I can't think of a game from the 8-bit era that I like the story of more. It's been in my top 10 list since the day I completed it. The Shotaro Ishnimori manga adaptation is excellent too, of course – he was a great guy to work on a Zelda property.
I don't know if I need a sequel or spiritual successor to Zelda 2 (there are a ton of clones of it on the NES and especially the Famicom), but I do think it could use a remake. People, even hardcore fans of the series, always dismiss it as "that weird hard one", and it is both very weird and very hard, but it's a really terrific, unique game that blends fast-paced action and slow, intellectual discovery very well. If you play it, I truly would advise you
not to use a guide, cheats, or any form of walkthrough. Take the time to play the game by its rules, and you'll learn to love it.
Outside of 2, I guess I'm a weird pariah in the Zelda fandom because the other ones I like most are 1, Minish Cap, Four Swords Adventure, and Breath of the Wild (I haven't played ToTK, but I'm pretty sure I'd like it, too). I'm not crazy about Link's Awakening (any version, and I think the remake's graphics are honestly pretty awful) nor really any of the pre-BoTW 3D ones, so feel free to murder me in my sleep. I'd really, really love to play Zelda's Adventure someday – I hope it gets decompiled, because the game looks right up my alley. The 80s cartoon is absolutely fantastic, too, of course.