I haven't been to Fiji for years however I can provide a little tip. If you are looking forms less touristy experience then I would suggest an island rather than the mainland. Oh, and avoid resorts that offer 'kids club' hopefully then it will be less touristy. When are you going? Try to avoid cyclone season.

Beqa and Taveuni are more remote areas with rainforest vegetation - good choice if you want less touristy - there is 4 star accommodation available but more rustic options at cheaper rates. Diving here is supposed to be very good and around Pacific Harbour there are adventure activities such as canoeing, whitewater rafting and jungle surfing.
Mamanuca Island group is the most popular area for tourists as it is only 45 minutes by ferry. Accommodation is more expensive but the bures are better appointed and the food is of a higher quality. Of the Mamanuca Islands Beachcomber is a backpacker island with a party vibe, Treasure Island is for young families and couples, Mana the big Island has 2 backpakers and a resort, Castaway is a well known four star family destination and has a dive school and parasailing. Malolo Island has 3 resorts Liluliku, Malolo and Tropica( renovating not yet open ) Likuliku is stunning 5 star with overwater bures or beachfront amazing food and craftsman built in the traditional Fijian fashion. Inlaid woodwork, thatching,timber flooring and outdoor stone and timber showers but it is very expensive. Malolo is a 4 star resort with a very friendly feel, beach side bures , day spa 2 pools and snorkling off the beach. The food is very good at both restaurants and the service at both resorts is excellent.
Tokoriki is couples only - mainly honeymooners ( have own dive shop), Matamanoa is a small island with less than 20 bures and has their own dive shop and a nice house reef. Musket Ccove and Plantation Resort and big resorts - Plantation is older a bit run down. Musket is better and offers parasailing.
Subsurface Dive operate from most of these resorts google the website or search mamanuca diving for details.
Most resorts offer fishing with a hand line or trolling.

Have a wonderful trip

www.coral-sea-villas.com.au

Ok people, I have had lots of good advise thrown at me and I came up with a basic plan I believe. Please let me know what you all think. My biggest concern right now is having stuff to do outside of diving. I very much love to dive but also like to do things outside of diving that will keep me entertained everyday. I like the non tourist areas but at the same time I do enjoy going into town and having places to eat, drink and socialize. That is also a concern for some of the resorts. I have heard a lot about Naigani resort but I'm concerned that I may just run out of things to do there outside of diving. I truly have ADHD and need to be active, not just sit on a beach. That is where you all come in since I have never been to these places. Of course, the main activity would be diving so I do want to go to the best sites(and hopefully knock off the Hammerhead bucket list item) but I'd day I will probably only dive 4-5 days out of every week. So here is the plan, and please feel free to break it down and adjust it, like I said I like relaxation but I still need things to do and need to have places to socialize.

Arrive in Nadi
5-7 days at Uprising Resort in Pacific Harbor(They have a stay 5, pay 4 special that includes zipline and rafting)
Shark Dive and possibly Beqa Lagoon dive

5-7 days at either Coconut Grove or Nakia on Taveuni
DIVE!!!!

5-7 days at some other location, and at this point I really have no clue where. Like I said I want things to do, great dives are for sure but even hikes, city exploration or whatever else might be fun.

Then maybe 2 days in Nadi before we leave

All of things are negotiable, I just did a bit of research on trip advisor and so on and some of the resorts are just too pricy and these looked fair. If they are horrible, please tell me, if the area is horrible, please tell me. I'm still planning so anything goes! Thanks everybody.