My family and I took a trip to Helen in July and really enjoyed ourselves, very relaxing and beautiful area. The best thing we did, however, was go tubing down the Chattahootchie River in individual inflatable tubes! What a blast! We went over and over again, and at $4.00 a ride (which lasted over an hour!) it was worth every penny!
Word to the wise -- the water is COLD! Also, be sure to wear shoes (a pair of sneakers would be perfect!) While the current is very mild and the water is not deep (ranging from just a few inches to 2-3 feet) I would also recommend you stay alert -- fallen trees and rocks can catch you by surprise and I did see one person with a pretty good cut on the foot.