Awesome Music: The original film trilogy had classic soundtracks by the likes of Pierre Bachelet, Francis Lai, and Serge Gainsbourg.
Darker and Edgier: The Joe D'Amato directed knock-off Emanuelle in America which features explicit bestiality and violent snuff movie themes.
Fair for Its Day: The old films have not aged well and are subject to a lot of Values Dissonance, but they were some of the first major motion pictures to feature a woman who was more or less firmly in control of her sexuality.
Hilarious in Hindsight: As mentioned below, the first film's soundtrack included a track that was a blatant rip-off of a Serge Gainsbourg. Gainsbourg himself would end up composing the music for the third film, Goodbye Emmanuelle.
Quirky Work: The Guido Crepax adaptation often veers into this territory due to his surrealist visuals. Special mention goes to his depiction of Emmanuelle's rape at the hands of Arianne, which cuts away to a scene where a gazelle is run down by a cheetah.
Another very strange moment for the character is showing up as the girlfriend of the exorcist in the bizarre Bruceploitation movie The Dragon Lives Again. Yes, that exorcist.
Sequelitis: The film series has a bad case of this, with dozens of loosely-connected sequels and a whole separate franchise of knock-offs.
Suspiciously Similar Song: The original film's soundtrack features some blatant knock-offs, like "Rape Sequence" (which is basically a shorter, jazzier version of King Crimson's "Larks' Tongues in Aspic, Part 2") and "Cigarette Act" (which is essentially an instrumental version of Gainsbourg's "Je t'aime... moi non plus".)
