Mexican musician Celso Piña is a pioneer in mixing cumbia with ska, reggae, rap, hip-hop, dub etc. working together with guys like Toy Selectah and Chic Sonido. His hit “Cumbia sobre el rio” is a milestone and was for many people (including me) the introduction to cumbia.
Here are some more of his songs:
[youtube=http://www.youtube.com/watch?v=e97isb0e5nQ&hl=en&fs=1&]