I used to live in Graftonia - all of me mates used to trek down to Corindi beach inbetween Coffs and Graftonia (Darlington park resort/caravan park) and it gets pretty packed in summer. Heaps of the opposite sex, plenty of people the same age as us - not alcohol scabbing 13 year old skanks. Good fun there, has a massive pool and spa complex, beach, golf course, tennis courts, restaurant, shop... and a shortish drive to Coffs.
All my mates and I find it a great time anyway, especially when the women trek over to our parties.
By the end of the night everyone has dissappeared with someone else, if you get my drift.