Immortality Science Fiction

Kind of a no-brainer—this sub-genre is about eternal life, existing for an infinite amount of time, immortality. It is something that humans have sought throughout history, or at least thought about.

Science Fiction presents immortality in one of two ways: (1) immorality is a blessing and full of limitless opportunity, (2) immorality is the end of change and full of ennui and stagnation. Regardless of the positive or negative view, a story about immortality includes the ideas of longevity (freedom from aging) and rejuvenation because immortality is undesirable without both.

Other Features of Immortality Science Fiction

Level of Real Science
Moderate. Stories within this sub-genre usually have a scientific reason for immortality—mutation or scientific development—and while the explanation is believable when readers are in the world of the story, immortality is ultimately not possible within our understanding of the scientific world and therefore completely speculative.
Level of Grand Ideas/Social Implications
High. What happens when we can live forever? This is a pretty big question and there are many possibilities that make for engaging stories.
Level of Characterization
Moderate-High. Immortal characters are a lens through which to view history, which can affect how well they are developed as individuals. On the other hand, detailing the effects of immortality on a person can make that character that much richer. The immortal character has had a long time to find him or herself and that translates to well developed character psychologies.
Level of Plot Complexity
Variable. There are different approaches to writing a story within the Immortality sub-genre. The story can be big and encompass eons, which means there is lots of history to cover and so there will be jumps from one even to another. This approach can have erratic pacing, though still present a vivd story. Another way to approach the Immortality sub-genre is to focus on shorter period in an immortal character's life. With this approach the author will have more control of pacing and plot development. There is also the quest for immortality. Immortality is the ultimate power and the search for it is an adventure, which leads to an action-packed plot.
Level of Violence
Low. Immortality means you can't die, so there's minimal violence most of the time—unless of course, the protagonist is the Highlander, then there's lots of decapitations.

Related Science Fiction subgenres

Transhumanism. Transhumanism strives for the improvement and eventual perfection of humanity—one such goal, at least for some, is immortality.
Speculative Fiction. Immortality and its advantages and problems are grounds for an engaging speculative exercise.
AI Science Fiction. One extension of Immortality is living forever by becoming digital versions of ourselves or transcending into another state of consciousness (ala the Singularity) by either merging with an Artificial Intelligence entity we create or creating Artificial Intelligence that transcends humanity, essentially living forever.
Singularity Science Fiction. Similar to Transhumanism (indeed part of it), but with the specific idea that humans will eventually reach a higher state of conciousness (posthuman) not directly but by creating Artificial Intelligence that will eventually reach beyond our own limitations to become an all-powerful entity.

Popular Immortality Science Fiction Books

1 The Immortals

By Harold Scarborough. A Russian biologist creates a serum that stops the aging process. The biologists financier intends to market it as a vaccine.
2 After Many a Summer Dies the Swan

By Aldous Huxley. This is the story of a Hollywood millionaire who fears death. It is an examination of American culture—narcissism, superficiality, and the obsession with youth.
3 The Lost Garden

By George C. Foster. There are survivors from Atlantis—they're immortal. This is their story of experiencing the world's history.
4 My First Two Thousand Years

By George S. Viereck and Paul Eldridge. Paul Eldridge. The Autobiography of the Wandering Jew. This novel provides portraits of historical and religious figures and intertwines social commentaries, philosophic observations, and history and science-based episodes.
5 Methuselah's Children

By Robert A. Heinlein. Part of the Future History series and the first introduction of the character Lazarus Long. The Howard families have achieved long lifespans through selective breeding, and financial wealth.
6 Forever is Too Long

By Chester S. Geier. A scientist discovers he is immortal and is at first happy—but then he watches his family age and die.
7 The Boat of a Million Years

By Poul Anderson The novel covers a group of immortals from the ancient past to the near-future. It shows their difficulties and quest to find others like themselves and then their departure from Earth and exploration of new civilizations.
8 To Live Forever

By Jack Vance. In a near utopian city lengthening someone's life is a reward the government bestows. And immortality is the highest honor, reserved for select few.
9 The Eden Cycle

By Raymond Z. Gallun. This novel depicts a future where immortals can live in any virtual reality of their choice.
10 Dancers at the End of Time

By Michael Moorcock. The protagonists go to absurd lengths to keep ennui at bay.
11 Commonwealth Saga

By Peter-F-Hamilton. A world where humans can re-life their bodies via clones with downloaded memories. There are many books in this series (three trilogies) but he has a specific stand alone that deals with the cost of 'living forever' called 'Misspent Youth'.
12 Altered Carbon

By Richard Morgan. Humanity can re-sleeve themeves by downloading digital copies of themselves into new flesh bodies. An interesting and exciting mix of cyberpunk and immortality SF with noir detective fiction thrown in. Exciting, violent, and addictive.