Which sci-fi titles (movies, books) do you consider comforting, cozy, something you come back to from time to time? For me, I guess it is The Matrix. Still holds up to this day, gets better with every re-watch, and gives me a sense of peace when I need it.
Octavia E. Butler's Xenogenesis trilogy (also known as Lilith's Brood Trilogy). I've listened to the audiobook narrated by Barrett Aldrich four times now, and I always discover some new angle to the story.