I certified about ten years ago then went on a cruise and dove in Grand Cayman, Honduras, Belize and somewhere in Mexico. Before certifying I dove in Hawaii and Cancun. Mexico diving sucks, at least the two places I went. In either Honduras or Belize (forget which one) we saw a hammerhead (well, everyone else saw it and kept pointing at it but I never actually saw it). The guide, who'd been doing it for 15 years, said he'd never seen one before that.
Anyhow, taking the fam to Hawaii in a month and I'm making my wife dive. My favorite dive was actually my first dive ever in Hawaii (circa '99) with the turtles. The kids will also snorkel in Hanauma Bay.