Arguably the most understandable spanish accents are from Lima, Bogota and the DF. And the accents you should avoid at all costs are the Bolivian, Chilean and Ecuadorian accent because they are seen with a bad light on another countries or aren't understandable (even for spanish speakers from another country). Also argie spanish is not the most easy too learn, neither the most "authentic" but it sounds cool and you could use it as a prop.
Girls love argie spanish che!
Girls love argie spanish che!