am from South America too(chile) and Garmin is a must. Ovi maps are great and all but not as updated as Garmin maps, Gmaps works too but with no offline usage is kinda diff.. i mean expensive for me. (cant afford the data plan :'( )
PLEASEEEE GARMIN!!!

also i think theres no tomtom or route66 for my country so if i dont get Garmin and their excellent and i mean superb maps,(just in case u Garmin guys are reading this) i will be left out in the cold.

again: PLEASEEEE GARMIN!!!