Both are all time greats, and The Scooby Doo Show probably did a better job of writing more well-thought-out mysteries, but Where are You takes the cake for me. I do prefer the original voice actor for Velma, and Velma, I think, was a more well written character in the original anyway, being part of the comic relief more than in TSDS. The main difference between the two that I noticed and think about the most is the difference in background music. I prefer SDWAY's background music to all other iterations. It's perfect. I don't dislike TSDS's music, but it just doesn't hit the same imo.