Bible Gateway
Not only is it the best Bible search engine, it has audio files of the passages. And you can compare passages from different Bibles on the same page.

Search God’s Word 
Offers a great number of study resources as part of the search result

Blue Letter Bible / Strong’s Number Search
Searches the Bible and returns a listing of all occurences of the Strong’s Number, displaying a KJV Bible, annotated with Strong’s Numbers next to each English word. Plus, it displays a Lexicon definition for each Strong’s number.

 More Resources

• Unbound Bible - good for if you wish to search in Greek or Hebrew or 42 other languages. Visit the site to use Non-English characters such as Hebrew, Greek or Russian
• American Bible Society’s King James Version - complete edition online
• Gospel Hall - multi-version bible search
• Religion Explorer - search engine and directory that only lists religious sites
• Bibles from before the year 1000
• Codex Sinaiticus is one of the most important books in the world. Handwritten well over 1600 years ago, the manuscript contains the Christian Bible in Greek, including the oldest complete copy of the New Testament.