The Walking Dead is a bad example because it doesn’t strictly follow the comics (Andrea lives, Dale dies much later, etc in the comics). I actually read all the books from the A Song of Ice and Fire series before I started watching the show. The books are of course much more detailed than the show is (much like the Harry Potter movie franchise), but still a pretty faithful adaptation. The thrill is 1) knowing what’s coming and being excited to see it visually/see how it’s adapted to screen, 2) seeing how they change things to adapt to screen better, and 3) just seeing your favorite (and least favorite, like Joffrey) character come to life and well, come to death too. I threw my book across the room when the Red Wedding chapter happened, and cheered when Joffrey died. Seeing those scenes happen on screen was so fun! It doesn’t take any of the pleasure away from watching the show, I promise.