I would recommend 'The Gaucho Martin Fierro'. It's a classic Argentine work that tells the story of a gaucho in a somewhat straightforward manner, which is great for those new to Argentine fiction. The language used is not overly complex, and it gives a good sense of Argentine culture. Also, 'The Invention of Morel' by Adolfo Bioy Casares is a good pick. It has an interesting and engaging plot that can draw in new readers and introduce them to the creativity of Argentine writers.
For beginners in Argentine fiction, 'Heartbreak Tango' by Manuel Puig can be a good choice. It has a clear narrative structure and deals with common themes like love and loss in a way that is easy to follow. The characters are vividly drawn, and it gives a taste of Argentine life. Another option is 'Rayuela' by Julio Cortázar. While it has a more experimental structure, it's not too difficult to get into and can open up a new world of reading experience, showing the unique style of Argentine literature.