I'm not a big fan of Hebra, like others have said, and Death Mountain is a bit of a one note area for my tastes. I like volcanoes, but there wasn't enough variety for me to really enjoy the area that much. Faron is annoying to navigate because of the terrible water mechanics, but the visual more than makes up for it. I think Death Mountain takes the cake for me though. I don't like Breath of the Wild's Gorons very much, particularly when compared to the Zora a couple regions over, the Divine Beast there is my least favorite, and there just isn't as much fun stuff to do there. Hebra would be worse, except I love shield surfing, and Hebra's great for it.