No one is an island. We all achieve success through our own skill and hard work, but also through a network of people who teach, hire, refer, and otherwise help us along the way. But what if you had to distill your thousands of contacts down to just five? Here’s how three top networking experts would make the cuts.

Of the three experts, the one whose philosophy most speaks to me is the one who says you should look for people in certain roles to add to your network:

Harvey Mackay chooses his five by role.

1. Best friend. It might be your spouse or a trusted friend, but you have to have a confidante and sounding board--one person in the world to whom you can tell everything and anything, Mackay says.

2. Doctor. Find a medical expert who can give you good counsel about your health and help you make well-informed decisions if you or a family member gets sick.

3. Legal expert. Whether you need business or personal legal advice, having a lawyer in your network helps you identify the type of legal counsel you need for any given situation. Your attorney can be a sounding board for tricky situations to ensure you act in your own best interest.

4. Mentor or coach. Everyone has room to grow, Mackay says. Find the person who can teach you what you need to know to get better and develop a relationship with him or her.

5. Business advisor. When you need to make decisions in your business or career, you need a straight-shooter to give you objective advice--even when it’s not what you want to hear--about the next best moves, he says.

I think this is excellent advice, and I concur -- every person should have these five people in their network.