If you are planning with friends North Goa is best and planning with family members then South Goa. Place for accommodation is pocket friendly in North Goa as compare to South, if you are lucky and good in negotiations you could also get a good place in South with less rental. Keep note if you are renting a vehicle from North Goa conform if it has permission for driving it in South Goa... as they have some rules.... and never drive two wheel without helmet, as you could be fined for it.