Good shore diving narrows the options right on down. Locations known for it:
Possibly the best:
1.) Bonaire - long strip of west coast lee-ward side of the island, reef close in, dive industry infrastructure very conducive to high volume shore diving, coast-hugging road with multiple dive sites close to each other, but most shoreline isn't sandy & you walk in over iron shore so thick soled boots are needed. I've been to Bonaire 8 times; never dove Curacao.
2.) Curacao - by reputation IIRC, similar to Bonaire, but bigger, more non-dive stuff to do, more sandy beaches with easier entries but longer swim outs, the dive industry infrastructure isn't quite as shore-diving focuses (e.g.: not a lot of rental trucks loaded with tanks in the back going up & down the road), and the road paralleling the coast doesn't hug the shore line as closely so you're apt to do more driving between sites. If I got any of that wrong, someone will be along to correct it. Airfare to get there tends to be a little cheaper.
Bonaire tends to be warm, minimal current, nice reefs, pretty fishy, but not a lot of big stuff. Big would be tarpon, green morays, cubera snapper, tiger grouper, barracuda (most I saw there small), green & hawksbill sea turtles, the occasional string ray, rainbow parrotfish.
In Bonaire I have not seen sharks, black grouper, gray angelfish or pork fish, interestingly enough.
While boat diving is 'good' in Bonaire, a number of people consider it not worthwhile since it's mostly the same diving you do from shore. Neighboring Klein Bonaire, a little island, is an exception, but the diving there's said to not be all that different. From what I'm told Curacao has some boat sites that are more 'special.' Bonaire's mainly boat access sites spoken well of include Small Wall (which to me just looked like a bigger version of The Cliff) and Rappel (? spelling, which I haven't done).
Bonaire vs. Curacao.
Said to be good:
1.) St. Croix.
2.) Maybe Grand Cayman.
A thread discussing St. Croix as a dive destination.
Richard.