Note: I bump this post to the top whenever I add a link. New resources are in bold.
e-Sword Bible Windows software that has 25 free versions of the Bible, 7 Greek texts, 3 Hebrew texts, the Latin Vulgate, and 45 foreign language translations. There are a number of the top commentaries, dictionaries, and books like the Ante-Nicene Fathers, Foxe’s Book of Martyrs, and Finney’s Systematic Theology. I have written a full review of this program.
Bible Tools — Online commentaries where you can view Clarke, JFB, Wesley, Henry, Robertson, and others comments on a verse.
Blue Letter Bible — Online Thayer’s Lexicon, KJV translation count, and lists all scriptures where the Greek word occurs.
Greek & Hebrew Reader’s Bible — Online Greek New Testament and Hebrew Old Testament text that allows you to hover over each Greek or Hebrew word and see the Strong’s number, a Lexicon definition, and the parts of speech, number, person, tense, voice, mood, case.
Biblos Greek-English Interlinear New Testament — The Greek words are in a Greek font and can be hovered over to show parsing. You can only reference verses by chapter, and not by verse. Very nice tool!
Koina Greek Cases Explained — Gives a detailed explanation of the 5 Greek cases.
Online Greek Grammar Tools — A list of good Greek grammar tools from the Institute of Biblical Greek.