While I know this sort of question is completely hypothetical, I find it hard to answer. So much of our experience with a game is colored by outside influences that it's hard to say if we'd experience it the same way again. With this idea in mind, if I were to erase one game/series from my mind to re-experience it for the first time at my age now, I'd probably choose the Zelda series. Mainly because it is such a figurehead of my adolescence, that it is hard to remove personal experiences with the games from the actual product. It would be interesting to see if I would still love games like Twilight Princess or Wind Waker if there wasn't the months of anticipation that proceeded them or if I'd still get sucked into the lore and world of the series despite not being a kid and having hours on end to let my imagination be completely taken by the sense of place these games so expertly articulate. As much as I love the series, I doubt I would love it as much if I were to re-experience. I'd likely still find the gameplay engaging and fun and be impressed with the level design but I don't know if I would be as taken by the lore, world-building and atmosphere as I did when I was 10. I'd likely still really enjoy them and maybe even love some of the games, though I doubt I would hold them as highly as I do now (ie; I don't know if I'd still consider games like Ocarina of Time and Twilight Princess to be some of the best experiences I have ever had with a work of fiction period if I didn't experience at in the time in my life that did and have the personal history with the series that I do as a result).
However, if the question is to re-experience it like we did the first time - my answer would remain the same as my experience with games like A Link to the Past, Ocarina of Time, Majora's Mask, Wind Waker and Twilight Princess were some of the highlights of my youth and I'd love to enjoy something again as much as I did those game in my later adolescence.
My alternative answer is The Last of Us though, because upon completing it all I wanted to do was re-experience what had just transpired as if it had never happened. It had been years since I was as taken by a game and it's atmosphere and characters as I was with The Last of Us, that once that ending settled in all I wanted to do was re-experience that feeling. Such an amazing game and an experience I'll always hold in high regard.