Biting the Sun - Tanith Lee
This book is actually two novels in one, as it's a volume composed of Don't Bite the Sun and Drinking Sapphire Wine. Both novels are set in the same universe and focus on many of the same characters, so it makes perfect sense for them to be put out in one volume, particularly as I feel the first book is in desperate need of a conclusion that Drinking Sapphire Wine provides for it.

The people of Four-BEE live in a world where both young and old, but especially the young, can experience any pleasure they like, to the extent that if they get bored with their personal appearance they can suicide and wake up in a new body, male or female, in all sorts of variations. It's almost the ultimate in hedonistic fantasies, with as much sex and drugs as you like as well, and littered with its own slang and attitudes.

Our hero is one of the Jang, embracing it all with enthusiasm, until she gets to a point where the realisation sets in that it's all pretty meaningless. From there on, she begins to buck the system, to the point where (in the second novel) she's living as an outcast from polite society when her idyllic existence is rudely interrupted by the arrival of others who want to follow her example.

It's a lovely piece of world-building, with our protagonist in particular being one of the most interesting characters I've seen in a while. She's not perfect, by any means, and her motivations aren't always clear-cut, but her enthusiasm for whatever she's doing seems to carry the books along with a will. Fortunately there's still a lot of this author's books out there for me to try, and I'll definitely be keeping an eye out for them.