Intelligent primates abound in SF literature, but there's plenty left to be mined in that vein. I'm reading through the award nominees on the Free SF Online site, and read this little gem tonight. Rachel in Love is a story I am happy to recommend.
Rachel is a chimp, abandoned when her master dies. But she is not an ordinary chimp--she's had a personality overlay, from the researcher's deceased daughter. This has augmented the chimp's communication skills, and she now acts as his daughter herself, though she is in some sense aware that she is a chimp.
This is the real strength of the story--Rachel is aware of being both a chimp and having been a human girl, and the story captures that mix and confusion perfectly. This stranded being has to respond to the terrifying situation of being left while she cannot fend for herself. Murphy brings other humans and chimps into play in the process of Rachel discovering herself. It leaves you convinced you can really imagine what it would be like to be Rachel. And it's an exciting, emotional story as well.
Rachel in Love, got the Nebula, and was nominated for a Hugo in 1988 and 1987 respectively. No surprise at winning, it's one that will stay with you for awhile. 4 stars.