I regrettably did not grow up with these two NES classics (my adventures with Link started with Link's Awakening DX on the Gameboy), but that doesn't mean that I don't have plenty of fond memories of when I finally did get to experience them. The first time I played the original Legend of Zelda was on the GBA re-release. One of my best friends got the game at the same time and we had a blast playing through it. My friend had grown up with the game so he knew a lot more about it than I did. We had a lot of fun trading tips on where to find secrets and sharing our frustration with Darknuts and Wizzrobes. I have a lot of fun going back to Zelda I because I'm much better at Zelda games that I was when I first played through it and it's a fun game to try to get skilled at. It's also just a remarkable adventure that still holds up very well today.
I picked up Zelda II for the GBA as well, but I could only make it to the second dungeon before giving up. I put off playing the game for years. Finally, a different friend of mine who had recently played through the game himself advised me that it really wasn't that hard after the Death Mountain area and was actually a really great game. Well, I'm glad I listened to him because he was right! I finally got around to completing Zelda II on the Wii Virtual Console for the first time in 2011, just in time for the series' 25th anniversary and the release of Skyward Sword. The game wasn't nearly as difficult as I had thought it would be and is actually a really fun adventure that I enjoyed from start to finish. Completing the Great Palace for the first time was one of the most triumphant moments in my gaming career!
I've since played through Zelda II a second time in its original NES incarnation. It's a really underrated game that's very satisfying to play and I think more gamers should give it a shot, especially if they like good adventure games.