The best harness is the one you find the most comfortable.
Two styles are avilable - waist or seat. Seat harnesses allow you to sit down and really load up the board and fin while using a bigger sail and speedsters love them. Waist harnesses allow you to stand a little more upright and give you freedom of movement for wave riding, freestyle or just plain cruising. With a higher hook position the waist harness also makes hooking into your harness lines heaps easier and therefore is a great way to go if you are just starting out.
Click here to check out how to choose your Harness Lines.