for a diving/non-diving mix. Bonaire can be too, it really all depends what the non-diver wants to do. Bonaire is on average quieter but a fine place to go if she just wants to snorkel, bike, vegetate, and the similar things mentioned. In Curacao you can still do that stuff, there is certainly more shopping, and the city and harbor can be pretty interesting to explore. Generally much more "civilization." Curacao has the advantage of direct flights on American. Opinions differ but I think the diving is similar between the 2, and my preference is for Curacao diving just because I find a little more variety. So whatever floats your boat.
As far as hotels, I still think the best place for a diver on Curacao is Habitat, but it's bit out of the way if your other half doesn't dive and needs "stuff" to do. Lions Dive is ok, in the middle of a lot more activites and stuff, and much closer to town. The Marriott is also close to civilization and quite nice if you want the big resort experience. (I wandered around there one night in August and it looks like it is developing more of a "real" dive operation which wasn't true years back, but I don't have any first hand experience. Anyone tried it?)
Breezes in the same general area as Lion's Dive. It may be a fine choice for you or not, but it's definitely the sort of place a mass-market travel agent (rather than a dive specialist) would send someone. There's other nice and interesting looking places to stay in Curacao (such as Kura Hulanda or Avila Beach) that I'm sure aren't on the radar screens of the average US travel agent. They're not set up for divers though.
On Bonaire almost anyplace you'd stay is reasonably close to town and tailored for the convienience of divers.