Pacific Island for 10 days - which island to choose??

Hi there,
My partner and I (early thirties)are wanting to spend minimum 10 days in the Pacific Island in june or july this year. I have done some research, and every island seems to have their own interesting points, and I can't seem to be able to focus on any particular, and though I could do with some recommendation!

We are departing from Brisbane, Australia, and would like a flight that is not over priced. Without going budget, we do not need to be 5 star, and we are searching for a beautiful piece of paraside to chill, do a few activities such as diving, snorckeling trecking etc.
I know a fair bit about fiji, but would like to get a vibe of the other island, such as Samoa.
I would most appreciate your feedback!
Thanks!

For something a bit less travelled look at Solomon Islands and Exploring Solomons.
Just 3 hours from Brisbane, on Solomon Airlines, Pacific Blue or Our Airline.

See this thread from a couple of days ago asking the same question...

Pretty much anywhere would fit your criteria. Fiji & Vanuatu generally have some of the cheapest airfares from Brisbane.
I don't recommend independent Samoa. It had some nice parts, but overall it left a bad taste.

Vanuatu will be a good choice also. See this for reference http://www.travelinhand.com/blog/tag/vanuatu

Bora Bora, French Polynesia, is the best island in the Pacific.