I think that's the brilliant part of learning English, the best books get translated to English, but may not necessarily be translated into your native language.

For science fiction, I'd be LOST trying to read Stanislaw Lem in Polish or Roadside Picnic in Russian. No idea if any of that is in your first language.

Take a look at the Cemetary of Forgotten books series by Carlos Ruiz Zafon as well, translated from Spanish, or in Spanish if you can read them. Not really fantasy, more like gothic romance, all quite good.