Initially? The Genre.
There are times you feel like you want to read some horror fiction, or plunge yourself back into classic books. There's also that time where you just want to levitate back into happy ever after land with romance. So when that time comes, you just won't stop yourself from scratching that itch and bury yourself in book heaven.
So when I know what genre I want to read, I then look into the reviews. I may not agree with it after I've read the book, but I like seeing different perspectives first so I can pay closer attention to the book while I'm reading it, to see if I agree with some observations made by some readers or not.
These things are what mainly makes the books appealing to me, but there's moments where the superficiality sinks in and you just got to look into the book because it has a gorgeous cover!
