The decision depends on your BAC at the time, your prior record, and the specific circumstances of the stop. Refusing triggers a license suspension of 6 months to 1 year on a first refusal and a separate civil charge, but eliminates the per se BAC evidence the prosecution would otherwise use. With a prior DUI or refusal in the last 10 years, a refusal becomes a misdemeanor with possible jail time. Taking the test at a low BAC may produce evidence that supports your case. Taking it at a high BAC (over 0.15) produces evidence that strengthens the prosecution. There is no universally correct answer. Most experienced DUI lawyers advise calling counsel from the police station before deciding if at all possible.
