Bali is our favorite destination - either underwater and topside (though we typically avoid the main tourist area at south); more than a dozen trip in 15 years.
As Valdimir said, bali offer anytype of tropical diving - and at any budget.
Plenty choices - from Northwest bali move clockwise you'll find Gilimanuk, Menjangan, Pemuteran, puri jati, lovina, kubu, tulamben, seraya, amed, candi dasa, padang bai and the islands nusa penida, nusa lembongan - if we you like pelagic and weird mola-mola in chilling water.
Liberty wreck at Tulamben probably the easiest wreck diving in the world - it's fish soup with its resident 1.2m barracuda and humphead parrotfish school like a tank regiment at early morning diving.
Although few people diving Sanur and nusa dua, but it's not really diving destination.
You can check to regional forum Indonesia to get more detail information about bali or simply search Bali in this forum.
If you're asking dive club, Indra has answered your question and if you men dive center, Bali probably has more than hundred dive center/shop.