Hilma Hooker is a 'signature' dive. Fin around to the far side of it, as you're more likely to see tarpon or barracuda there in my experience.
1,000 Steps is a northern site with a scenic 60 something stone step stairway that makes for nice pics, & is a good dive.
Past that, the road is one way & commits you to a long drive around to get back. Karpata is liked by many, and Tolo (a.k.a. Ol'Blue) is another site on that stretch that's a decently easy entry & a good dive.
Oil Slick Leap is nice site, reef very near shore, with a nice giant stride (maybe a 6'+ drop?) that's another 'signature' Bonaire dive. Plus I see neat creatures here fairly often. Be sure the ladder is there; you have to have it to get out.
Andrea I & II are generally good dives with easy entry.
The Cliff has a small wall, fairly shallow, and is largely unique there.
Bari Reef has a rep. for high species diversity. I dove it; good dive, but can't say it was head & shoulders above others on Bonaire. Not a bad one to be able to say you've done, though. The yellow rock & road to it are on a 'round-a-about,'
I like Windsock for easy entry & exit near the large pier, which is also useful to know your exit when coming out on night dives.
Sweet Dreams is a far southern site with a particularly lush reef, that reminds me of Karpata.
That's 11 sites. If you do boat dives, too, you may find these are enough. But there are others people really like - Angel City, Red Beryl, etc...
Richard.