The landing strip theory took a battering once people pointed out the lines aren't actually flat or reinforced enough to land anything on, but I'm not ready to fully bury it either. What gets me is the sheer scale - you only really appreciate them from the air, so why build something that massive for ground-level rituals? That part still nags at me.
Doesn't have to be nuts-and-bolts spacecraft either. If you're into the idea of non-physical craft or interdimensional contact (which based on some of the NDE accounts I've read, isn't as daft as it sounds), the lines could've served a completely different purpose that we're still misreading as "landing markers" through a very modern lens.
What does everyone else reckon? Anyone looked into the water channel theory as an alternative? I've seen that get serious academic attention lately and it's genuinely compelling, but it still doesn't explain the animal geoglyphs to my satisfaction.