All of Hilton Head is wonderful. Hilton Head is all about the beach and golf. So if you want the beach, rent a place on or within walking distance to a beach. If you just want to relax and play golf, almost any rental will meet your needs. Great restaurants are plentiful, so you'll have good access no matter where you are on the island. Many of us can tell you good/bad things about a particular location once you come up with a possible rental.
My first choices for a timeshare rental would be one of the Marriott resorts on the beach, in order of preference: Grande Ocean, Barony Beach, Monarch (a bit older but in a great location) and SurfWatch (the newest, but a bit longer walk out to the beach). Another great resort within an 8-minute walk of the beach (with some reasonable rental rates on Redweek and other owner-listing sites) is Waterside by Spinnaker.