What are some of the best translated fiction books you've read?

The Cyberiad by Stanislaw Lem.

A part of the translation into English:

Klapaucius thought, and thought some more. Finally he nodded and said:

"Very well. Let's have a love poem, lyrical, pastoral, and expressed in the language of pure mathematics. Tensor algebra mainly, with a little topology and higher calculus, if need be. But with feeling, you understand, and in the cybernetic spirit."

"Love and tensor algebra? Have you taken leave of your senses?" Trurl began, but stopped, for his electronic bard was already declaiming:

Come, let us hasten to a higher plane,
Where dyads tread the fairy fields of Venn,
Their indices bedecked from one to n,
Commingled in an endless Markov chain!

Come, every frustum longs to be a cone,
And every vector dreams of matrices.
Hark to the gentle gradient of the breeze:
It whispers of a more ergodic zone.

In Riemann, Hilbert, or in Banach space
Let superscripts and subscripts go their ways.
Our asymptotes no longer out of phase,
We shall encounter, counting, face to face.

I'll grant thee random access to my heart,
Thou'lt tell me all the constants of thy love;
And so we two shall all love's lemmas prove,
And in our bound partition never part.

For what did Cauchy know, or Christoffel,
Or Fourier, or any Boole or Euler,
Wielding their compasses, their pens and rulers,
Of thy supernal sinusoidal spell?

Cancel me not -- for what then shall remain?
Abscissas, some mantissas, modules, modes,
A root or two, a torus and a node:
The inverse of my verse, a null domain.

Ellipse of bliss, converge, O lips divine!
The product of our scalars is defined!
Cyberiad draws nigh, and the skew mind
Cuts capers like a happy haversine.

I see the eigenvalue in thine eye,
I hear the tender tensor in thy sigh.
Bernoulli would have been content to die,
Had he but known such a2 cos 2 phi

That's not the whole story; along with this epic translated poem, there's this whole saga of (among other things) the two inventors trying to work on a thinking machine. This thing that makes the poem is one of the prototypes; one of them starts saying 2+2=7 and gets mad when one inventor starts yelling at it that it isn't, and chases them both up the hills and into a cave trying to kill them... it's just great. It's fantastic. The whole thing is great, and it's translated into English flawlessly.

From English to French: the Discworld series, translated by Patrick Couton. They're what made me want to become a translator in the first place.

From Tamil to English, Women Dreaming by Salma. From Chinese to English, Strange Beasts of China. Pretty much all of Tilted Axis Press's works, actually, and Charco Press for LATAM has some wonderful stuff too.

Spanish to English:

100 years of solitude

Love in the Time of Cholera

Japanese to English:

The Tale of Genji

Russian to English:

The Master and Margarita (one of my all time favourites.)

In The First Circle (the recent uncensored edition)

All in English because I'm an Anglo moron who only speaks one language.

Crime and Punishment (Ready translation)

The Stranger (Ward translation)

Ficciones

Literally anything by Hermann Hesse (maybe my favorite author)

The Best of World SF anthologies 1 & 2, edited by Lavie Tidhar have stories from all around the world, often translated into English. Some of those are fantastic, and often have a really different “flavour” to a lot of western sci fi

The Invincible was retranslated in 2016 I think. It's not bad. Explores the idea of none organic, or rather silicone based, life.

The accursed kings by Maurice Druon, translated by Humphrey Hare Rubáiyát of Omar Khayyám, translated by Edward FitzGerald In a Dark Wood Wandering by Hella S. Haasse, translated by Lewis C. Kaplan Beowulf, translated by Seamus Heaney ...among others

I own it but haven't read it yet, but apparently Edith Grossman's translation of Don Quixote is supposed to be great. Also I just learned she died a couple of weeks ago, RIP.

I can't speak for the translation quality, but I enjoyed Reverend Insanity.

The Unbearable Lightness of Being by Milan Kundera was published in French and then English before being published in its original Czech.

The P&V translations (Russian to English) of both Crime and Punishment and Demons by Fyodor Dostoevsky. Both these books have made me fall in love with Dostoevsky's writing. I also liked the Hapgood translation (French to English) of Le Miserables by Victor Hugo.

La Disparition by George Perec in French, translated to English as A Void. Neither version uses the letter 'e'. I think the French original is better since the translator had to cheat a bit with the numbers (5 and 26 appear frequently for self-referential reasons, and when spelled in French don't use e, but are translated as numerals.) but was still impressed. I read the side-by-side translated version, although I'm only marginally literate in French.