Bora Bora is definitely among the most beautiful settings for diving. As far as being a top destination? Depends on what you're looking for. Not the most beautiful reef scenics (in my mind hard coral isn't as spectacular as the soft corals in Fiji for example). Good bio diversity, lots of neat critters, and definitely if you're looking for the big boys (sharks, mantas) it has those in abundance. Absolutely beautiful island and lagoon. Ranks among my favorite dive locations (though in all honesty, for all around diving/scenery/lifestyle I might like Moorea in French Polynesia better).
Also if it matters to you, one of the most romantic destinations you could hope for.