I haven't been to the Big Island yet but my current island ranking goes
Kauai > Oahu > Maui
Loved Hana but the road to get there was not enjoyable at all. Sometimes you forget you're even on a tropical island. Didn't realize how much of this island is a desert in comparison to the other islands. Lots of resorts and hotels, every beach is pretty much the same, not as many fun adventures like I had in Oahu or Kauai. Even the food has been average despite picking recommended restaurants with 4.5 stars or higher (except for Prana Thai in Hana, that place was amazing).