I very much like the Sierra Elegant Beauty Click. . I have made about 50 of these with no problems. . Great ladies' pen based on size.
I also like the bigger Sierra Click .... it would probably be my first choice .... I do a lot of these. . Of all click mechanisms this is my favorite. . I have made over 100 of these and had no problems at all.
I also like the Long Boy which Mark James mentioned but the click is a bit mushy .... however, I really like this kit overall. . I make it as a single barrel pen and love the 4" barrel length when made this way. . As far as the clicker itself, this is my second choice. . This is a new kit in 2016. . I have made about 15. . No problems so far.
The worst clicker, IMO, is the Dayacom Long Wood Clicker, sometimes called simple the Long Clicker or the Longwood. . My assessment is based on the noise of the click and the rough feel of the click action. . I have made about 30 of these ... no functional problems at all. . I also don't like the size and shape of the click button ... too big and ugly.