Rinse it actually. Real just recently launched a new software dubbed "Rinse." The program is designed to clean up your itunes database, update artwork and generally fix your broken metadata. It does so via a link up with Gracenote. The product does everything from fix your metadata, gather missing artwork, and eliminating duplicates and more.
While there are other programs that have claimed to do these things, the Rinse software is “smarter than other programs,†including iTunes itself. The site says Rinse’s “intelligent database technology†finds artwork, remove duplicates and organize an iTunes library even if song names are misspelled or incomplete.
The cost for Rinse is a mere $39 which for me is totally worth it. Upon my first "rinse" it located and removed over 4,000 duplicate songs from my library saving the dupes on my desktop in a folder for me to sort through and eventually delete. The sort hierarchy can be set up to your own specifications (either eliminate the shorter version of the duplicate tracks - or the lesser bitrate). I chose the bitrate sorting and am quite happy with the results. The album artwork tool is also great although it took more than 24 hours for it to locate and find all of my missing artwork.
Overall I recommend Rinse to anyone with an extensive iTunes music collection. In my view- the more music you have, the more room there is for error in your database... My only main issue with Rinse is the fact that it along with all other options on the market does nothing for the hundreds of files in my itunes library titled "track1." I suppose there is some human error that no machine can make up for.