Ok, The Finisher by David Baldacci, it's long but it's great. The Hobbit (because it's awesome, not cause it's science fiction, then read the Lord of the Rings than the Silmarillion) The Giver series by Lowis Lowery, I feel like you said you've read the Lunar Chronicles but maybe that was someone else, Idk. Undertow, can't remember who wrote it, Divergent series by Veronica Roth I think is just okay but it's fun to read, Piercing the Darkness by Frank Peretti, but it will keep you up at night, Yellow Fever(yes it's historical fiction, but I love science fiction as well and it's almost like it), and I'll think of others, browse my shelf, the works:)