I like both, but I've always leaned toward science fiction myself. I have an easier time finding deep and thought-provoking stories in the science fiction genre, and I tend to prefer its more emphasis on exploring what its possibilities mean and using them to examine ourselves.
Shikasta is incredibly good because it feels like you're reading something intended for a completely different audience who would understand all the technical and religious stuff going on, but you're just a modern human so you have to piece together what's happening based on your own understanding. The novel is from the perspective of a highly advanced alien culture who have their own religion and values and etc, but none of that is explained explicitly. It's assumed you know all that already.
Like the aliens view obsessive individuality and greed as a kind of degenerative disease resulting from flawed biology. Being disconnected from a kind of universal harmony.
It's rad. Read it.
yeah that sounds exactly my shit. im all in