Trying to figure exactly what it is about Vorkosigan that keeps me, I'd have to say there is an immense amount of heart in the writing. Here is a galactic empire and the characters are major movers and shakers in that environment. That's nothing new to sci-fi, but what is different about this series is how one of the protagonists, the Admiral Viceroy Count Aral Vorkosigan, gets teared up upon seeing his son after a long time away. That's what I love about this series. These characters truly love each other. Bujold doesn't just tell you they're extraordinary people and as the reader you just go with it, she shows you they are extraordinary. Another thing that instantly won me over is how hilarious the books are. I find myself laughing out loud while immersed in the story.
Most of the series focuses on Miles Vorkosigan, who is a very flawed protagonist. He is small, but not a dwarf. He was injured in a bio-weapon attack on his pregnant mother. His childhood was consisted of endless treatments to correct his brittle bones which was the side effect of his mother's attack. He is weak in body, but that seems to motivate him beyond most other men.
The story goes that the Vorkosigan series started off as a fan-fiction for Star Trek. Upon finding that the book was turning out to be excellent, but not having the rights to write a Star Trek book, Lois McMasters Bujold altered the names and the faces, creating her own universe to set the first book in. The first two books are about an improbable relationship, truly a space opera. Almost all of the sub-sequential books are about the first two book's protagonist's child, Miles Vorkosigan.
One interesting thing about this sci-fi series is there are no aliens, there are only humans and occasional alien animals on various planets. Many genetically altered and re-arranged humans, but no sentient aliens. There are centuries-old, zero-G communities that whose ancestors were born with a 2nd pair of arms instead of legs and has continued that feature through it's descendants, but they're still human. Hermaphroditus are rare, but in some colonies, quite common. There are colonies and empires that have deep, elaborate breeding programs and pedigrees. Even characters with gills. Lots of bio-weapons and bio-art. Nasty corers of the universe where powerful people cheat their way to immortality by growing clones and transplanting their brains into the new 'vessel'. The Vorkosigan saga is a nice Trans-Human setting. Never getting too technical for layman readers, however.
The official order of chronology, according to Bujold, is as follows (note the books were not written in this order):
- Dreamweaver's Dilemma in Dreamweaver's Dilemma (1996)
- Falling Free (1988)
- Shards of Honor (1986)
- Barrayar (1991)
- The Warrior's Apprentice (1986)
- The Mountains of Mourning in Borders of Infinity (1989)
- The Vor Game (1990)
- Cetaganda (1995)
- Ethan of Athos (1986) [EoA]
- Labyrinth in Borders of Infinity (1989)
- The Borders of Infinity in Borders of Infinity (1987)
- Brothers in Arms (1989)
- Linking sections of Borders of Infinity (1989)
- Mirror Dance (1994)
- Memory (1996)
- Komarr (1998)
- A Civil Campaign (1999)
- Winterfair Gifts (2004)
- Diplomatic Immunity (2002)
- Captain Vorpatril's Alliance (2012)
- Cryoburn (2010)