Josette,
I liked Leviathan in the beginning, too. I enjoyed Evil Barnabas! Jonathan Frid was great there, he was really scary!
When I first saw Leviathan I identified with the kids, especially Amy. Alexander and Michael were such bratty bullies, tormenting her and David. It did fall apart in the middle or end ... mostly when all of a sudden Jeb wanted to be "human" and become a "good guy". Give me a break.
I enjoyed PT 1970 too. It has one of my favorite characters of all DS time:
[spoiler]the very sweet natured and gentle Dr. Cyrus Longworth[/spoiler]
It's also fun to watch Quentin throw tantrums.