Well, within the Maldives, there's also the Waldorf Astoria (formerly Beach House Maldives), which my wife and I loved. But from what I hear about the Conrad, the WA snorkeling isn't anywhere near as good. Don't know about diving. OTOH, the basic room at the WA is a very nice OWB with an infinity plunge pool. And because it's smaller than the Conrad, it's perhaps even more or a couples-oriented place.

There are the very nice French Polynesia properties at Moorea and Bora Bora. Again, pretty couples-oriented, though I think Moorea less so than BB. And at Moorea it's easier to get out and about, with more to do in terms of exploring the island (well, at least compared to BB). Quite a small beach at Moorea.

The Conrad Bali is a wonderfully run property that I'd think a single person would be comfortable in. But the beach is ugly.

There's a new Conrad Koh Samui that's supposed to be very, very nice. But it seems to be somewhat isolated from the surrounding area. OTOH, there's certainly lots to do and explore on KS if you have a car. The rooms and property are supposed to be wonderful. But like Bali, it sounds like the beach at the property is lousy.

I don't know about the other Hiltons in Thailand or those in Hawaii.

Wish I could give an unqualified recommendation, but hope this helps nevertheless. You might want to search for existing threads that discuss great Hilton resorts, beach destinations, etc.