I would say the season 4 finale really freaked me out and the one with the russian mob gave me nightmares.

Revelations

The one about the eyes being removed.

The new season. Don't like where this show has gone. Way too much violence. Used to be more interesting and characters were fun - now just like any other brainless violent show. They are a dime a dozen. Still like the reruns

"To HELL and BACK, Part 1 and Part 2.. This is where the Mentally Challenge brother kidnaps people, kills them and feeds the bodies to his pigs.. Creepy!

antrax ones really freak me out cos u wouldnt see it coming

the episode mosley lane.the one where kids were geting kidnapped then kept till they say no then cremated.

Proof freaked me out a bit. Acid in my eyes or anywhere kind of makes me cringe.

A couple of the episodes freaked me out ,the one with the brothers in Canada who fed the victims to the pigs,the one where the unsub removed the eyes,any episode that included George Foyet ,and the most creepy episode of all is the one with Ian Doyle were he killed Emily it also brought tears to my eyes ,my favoritist episode is the one were they find out that Em isn't really dead of course

Here is a list: Lucky (3.08) - The guy was kidnapping women and cooking them and eating them, plus he had a BBQ restaurant where he was serving them as well and he had served one of the to volunteers who were helping in a search and recuse. To Hell... And Back (4.25 & 4.26) - where homeless people where being killed and then fed to pigs. Proof (7.02)