This one...
http://www.kingjamesbibleonline.org/
A poor implementation.
People should buy software like the olive tree reader that will synchronize a commentary or another translation with wherever you are, and turn on or hide a concordance as needed.
God’s word is best used with scholarly tools at hand.
Online stuff is okay if you are at some strange computer and need to reference a verse or two, but wholly inadequate in terms of speed and ease of use for devoted study.