By Heat Level: sweet, warm, spicy, hot, to hot to handle!
By Location: planet bound, shipboard, in orbit, everywhere
By Theme: comedy of errors, redemption, lost love, second chances, crazy first dates
By Genre: mystery, action/adventure, strictly romance, comedy, military, near-future, cyberpunk
By Author: alphabetical listing and nothing more
None of the above. I'll leave my suggestion in the comments box.