"There is no credible evidence that learning styles exist. While we will elaborate on this assertion, it is important to counteract the real harm that may be done by equivocating on the matter. In what follows, we will begin by defining “learning styles”; then we will address the claims made by those who believe that they exist, in the process acknowledging what we consider the valid claims of learning-styles theorists."http://www.changemag.org/Archives/Back%20Issues/September-October%202010/the-myth-of-learning-full.html
This video also puts the case nicely:
Give your students the gift of being research-based in your practice. It's the best gift you can give.