Ridge wine labels all look the same, so it's sometimes difficult to remember which one you really liked. Fortunately, if it says Ridge and Zinfandel on the label, it's going to be damn good whether or not it was the same one you enjoyed the last time.
Another good rule of thumb - if you taste a limited production wine and you really like it, don't settle on one bottle. Buy at least two instead so it's easier to share. We enjoyed two bottles of our 2006 Ridge Carmichael Zinfandel (96% Zinfandel, 4% Petite Syrah) last Saturday with Jeff's parents, Bob and Kathy. The first bottle was paired with an antipasto plate while we were on a gondola ride in the Coronado Cays. (A very fine time - check out the Gondola Company.) The second bottle accompanied a wonderful dinner at the Il Fornaio restaurant on Coronado.