If you want something you can read in one day off: “Elric of Melniboné” by Michael Moorcock. yes, it’s actually Fantasy, but shut up, it’s a damned good story for 150 pages.
If you want something lovey-dovey: Star Trek: The Next Generation “Imzadi” and “Imzadi II” by Peter David. About the love-triangle between Cmdr. William Riker, Counselor Deanna Troi, and Lt. Cmdr. Worf.
If you want something kickass: Star Trek: “The Eugenics Wars: The Rise and Fall of Khan Noonien Singh” (parts I and II) – Exactly what it sounds like. Also “Genesis Wave” parts I, II, and III. Both very good serials.
If you want something a little bizarre: “Split Infinity” by Piers Anthony. Takes place in a world where the average person is naked all the time, and clothes are considered sexy (and only allowed to be worn by those with a permit). Has a Fantasy-genre cross-story.
If you want something out-of-this-world: “Dragon’s Egg” by Robert L. Forward. A space-exploration team on Earth discovers a planet evolving at a hyper-fast rate (a revolution of the planet takes place every few seconds, years go by in hours, etc.) and watches the inhabitants go from primitive life-forms to developing religion, politics, etc. Very fascinating. Ignore the early-1980s view on what 21st Century technology will look like.