I will be in Atlanta for Memorial Day with my 20 year old daughters. We are thinking of heading to North Carolina for a the rest of the week. Does this make sense? Our thoughts are that we would like to rent a place for the week as a base. Then to go visit Charleston etc. Seems like there is a lot of difference of opinion on Hilton Head, Tigbee Island. ... We just want to relax, enjoy the beach, yet travel and see the area. I am just confused and need to make plans because time is running out. thanks

Well, Charleston is in SC and Savannah is in GA.
Why "North Carolina"? Do you want to go to those beaches?
Did you mean Tybee Island?
How far do you want to drive after you leave Atlanta?
Hilton Head would work as a base for Savannah and Charleston if you want to stay on a beach.
I'd probably stay a couple of nights in Savannah and them ove on to a beach near Charleston for the rest of your visit. I'm not a big fan of Hilton Head, but many are.

If visiting Charleston as a day trip during your stay at the beach is a priority, you'll probably want to stay somewhere in South Carolina instead of North Carolina. Pick a maximum drive radius from Charleston to narrow down which beach area you would like based on your budget, interests, things you might like to do or see, etc. There are lots of threads about beach lodging around the Charleston area and quite a few Fodorites that post regularly to help you out. There are no beach lodgings in Charleston proper, so you'll either need to look north or south of the city for the beach. If I'm not mistaken, it's at least a 2 hour drive from Hilton Head to Charleston. It's also about 2 hours from Myrtle Beach to Charleston.

In additon to the above info...many condos and houses in beach areas rent for a full week in the summer so if you plan on a couple of days in each place, you may have to stay in hotels and/or B&B's.

I would look at some of the islands adjacent to Charleston like Kiawah or Seabrook.

Thank you everyone for your input! You have narrowed things down for me.

I think you want to visit Charleston and maybe Savannah. You could do a loonnnng day trip from Charleston for that. You could also visit Beaufort on the way to Savannah. Stay on the beach up around Charleston for a few days, then go to Savannah for at least a night, visiting Beaufort on the way, and return to Atlanta from Savannah. There are so many more interesting places than Hilton Head.

There is an excellent article in Nat'l Geographic Traveler re: this part of the country (April edition).