(Or un-read/un-hear/whatever.)
This is prompted by one of the recent Doctor Who threads. I often wish that I could somehow magically un-see the episode “Blink” just so that I could have the experience of watching it for the first time again. It was so delightfully creepy and terrifying and awesome, and rewatching it is fun but not really the same.
The other thing that occurs to me off the top of my head is the moment in Jurassic Park when they see the dinosaurs for the first time.
There’s lots of movies I’d love to see again for the first time, but if I had to pick, say, five, they would be
Jaws
E.T.
Galaxy Quest
A Man For All Seasons
To Kill a Mockingbird
I’d love to read Gaudy Night for the first time again.
The only book I would really like to unread so I could once more read it for the first time is “The Hound of the Baskervilles” by, of course, A.C. Doyle.
Has what I think is the most chilling single line in literature “…they were the foolprints of a gigantic hound.”
God, I hate to do it but it’s so funny to imagine a story where foolprints make your blood run cold.
The Prestige.
Star Wars, just for the arrival of the Star Destroyer.
The Nutcracker (ballet).
I got some good responses when I asked a similar question years ago.
What song would you want to forget and hear again for the first time?
What a great question! I was just talking about this with my friends last week.
The episode of Buffy The Vampire Slayer entitled: “Once More With Feeling”
The series finale of Star Trek: TNG
Star Maker by Olaf Stapledon
Foucault’s Pendulum by Umberto Eco
The Waste Land by T.S. Eliot
Mariner’s Revenge Song by The Decemberists
Engine 143 by The Kossoy Sisters
Memento
Primer
2001: A Space Odyssey
Of course, I would have to give myself the disclaimer that yes, it gets less boring. Hold on until the crew wakes up.
*The Lives of Others. * And not just because of the foolprints.
Someone mentioned Memento, but I disagree…that’s just the kind of film I could see a dozen times, and still be discovering new things. (But maybe you have a point in that you can’t replicate the feeling of encountering its unusual structure for the first time.)
Most of the original *Twilight Zone *episodes.
This was going to be my main choice; I still remember the experience of being in the theater on opening day and how the entire audience was sitting there in stunned silence as the T.rex burst through the fence, and then I heard one guy a few rows in front of me blurt out, “holy shit!”
Most of the other movies I would mention are movies with “twists”, like Memento and The Usual Suspects.
In terms of books to un-read: I Am The Cheese springs to mind.
Difficult choice, but I might go with The Clan of the Cave Bear, by Jean Auel.
I so enjoyed this book.
Firefly.
Oh, for the thrill of hearing “Curse your sudden but inevitable betrayal!” again for the first time. 
Blade Runner – for the whole movie experience.
The Matrix - mostly because of that roof jumping scene where your suspension of belief is trying very hard to give up on you but the fact that Neo says “That’s impossible” keeps you in and then you’re in for a twist of a lifetime.
American Beauty – for that moment where everything comes unhinged and starts when Lester Burnham undresses Mena Suvari’s character. From then on it is the most relentless finale in the movie history.
I wanted also to add two David Lynch movies – Mulholland Drive and Inland Empire but these are always new to me when I watch them.
This, as well as Rocky Horror Picture Show and Ouran High School host club. The latter is one of my favorite animes, but I know all the lines and plot twists, which makes watching it again kind of unsatisfying.
Oh, me too! The first episode I saw was the one where the Simon and River are kidnapped by the hill people, and there’s something revealed in that storey that changes your perception of River. I’d love to be able to see them all from the beginning, without knowing what that episodes reveals.