If you live on the West coast HI is a great getaway for 3-10 days. You get to experience another culture (if you want to) but you are still in the United States so you don’t have to think about passports, customs, currency exchange, etc. Every modern convenience and luxury of civilization is available to you; you can pamper yourself or elect to “rough it” Hawaii style. Lots of hiking, boating, surfing, and other water sports.
Kauai is more for couples doing the romantic honeymoon thing (and I highly recommend it), but if you have kids in tow stick with Maui or Oahu. If cash is tight... stay home; fun things your kids will enjoy like a helicopter tour or boat rides cost money. Doing a vacation like this on the cheap is no fun. You will want to rent a car to get around and explore whatever island you go to. Do not get a car; rent an SUV. Yes, it will cost more but it is worth it.
I never get tired of going to Hawaii. These pix are from Oahu.