I have been doing some research on Javascript obfuscators.  Various handlers have done stories in the past on how to reverse engineer obfuscated javascript that does evil things.  But I would be interested in hearing what kind of obfuscators people have been finding being used in the wild.  Are you able to identify the obfuscator just by looking at it?  What are the hardest off-the-shelf obfuscators to reverse-engineer?  I will collect responses and post them throughout the day (unless you wish the information to remain private).

-Kyle Haugsness