If you can't afford Bora Bora, then go to Maldives. Otherwise Bora Bora has it beat by every measure. There's a reason that Bora Bora is the single most famous island in the world, for over a century. The scenery is dazzling. As for activities, they are both water small island vacations, and the "urban" parts nearby are not so great, so the real reason to be there is for the sun, sea, sand and snorkeling, swimming, boating. Peace, contentment and isolation. If you want something else (excitement, jet skiing, sky diving, discos with wild parties) then you've picked the wrong destination (that is available, in NZ or Sydney or Thailand, but not here). From US Bora Bora is much easier to get to, while from Europe Maldives are much closer (half a world closer).
The third option is Bali, if you want everything at a lower price. Much better value (bang for the buck) and with your choice of seclusion and privacy or action (changable daily).