The Legend of Zelda
A few years ago, my brother and I took a day on Virtual Console to see how far we could actually get in the game. We made it through five-ish dungeons before giving up. This game is really hard.
I can't believe how much I must have mastered it as a kid to be able to beat it on more than one occasion. Sitting down and playing it yesterday was an exercise in frustration. Yes, the core of the series we love is here... but it's still gameplay from the 80s. It's difficult to make progress and even using the save states on Virtual Console it's still full of frustratingly tough section.
I played through the first few dungeons last night just to refresh my memory. Although I love the open world, exploration, and core of the series in The Legend of Zelda it's just not a game that I want to spend my time playing all the way through.
I've been there and done that.
If you have never actually tried this first entry and you already love the Zelda series you truly owe it to yourself to at least spend a day with The Legend of Zelda for the NES. Pick it up on Virtual Console for your system of choice and just dive in to see where everything started.
It's kind of amazing how many elements from this first game carry through the series.