agree with dnadavis, it depends on what you want to see, Bahamas is a pretty sweet shark hot spot - I want to go there someday to dive with the tiger sharks among others. I'd love to go to South Africa or Galapagos for cage diving with Great Whites one day too... Also the east coast of FL, around Jupiter has Lemon shark migrations, and I heard those are really cool to see... can't remember if they also have any hammerhead migrations, but that would be cool too.