That's very, very debatable. Mummy is more thrilling, but Kong had a lot more character. It was a landmark attraction for it's huge, extravagant sets, larger than life AA's and it was one of the great "speil attractions" of the park, a tradition that goes all the way back to the studio tour in Hollywood. They really did tear down a classic. I think that's a distinction Mummy will never reach for various reasons; the largest of which, is that it simply feels hollow. Then again, the same could be said for any recent attraction that was spewed forth from the depths of hell... I mean... the unimaginative creative teams of Disney & Universal.
I haven't been introduced to a truly great attraction since Spider-Man 7 long years ago.