It was the original mainframe Zork from the 1980's which showed me that text adventures could do more than just the two word commands of the Scott Adams adventures. The breadth of the dungeon was astounding and I loved the variety of puzzles. My eighth grade self loved the experience.
Zork I reduced the original Zork into bitesized puzzles. I helped my nephews through this dungeon crawl over the past few months, only giving advice when the puzzle just wasn't well clued and I wanted to save them from trying everything. There is a nice feeling of exploring caves but there is so much that just doesn't make sense. The puzzles surrounding the (Spoiler - click to show)egg were particularly well-made.
Although this is a classic game that deserves all of the praise for inspiring so many to write IF, it just isn't that much fun as a game in 2022. Enchanter & Planetfall do a much better job of giving motivation beyond just gathering treasures.