The Farm in Dalton, GA. The greens consistently run 12+ for regular weekday member play.
It was a startling experience; I had never played at that speed before. To lip out from 10' for birdie, come to rest 20 yds. off the green and end up picking up was, um, shocking.
It did, however, give me a completely different appreciation for what it means when pros play the Masters and don't three putt all week.