2 of 4 added 798 characters in body

This Youtube video is a collection of every scene in which Darth Vader used Force Choke on someone in the two trilogies:

Wookieepedia's article on Force Choke lists the same instances for Vader (it also lists some from his time before he turned to the dark side and became Vader). Vader used Force Choke the following times in the films:

  1. Against Padme in Episode III.
  2. (Possibly) against the Rebel on the Tantive IV in Episode IV (he physically chokes him and lifts him off the ground, but it's unclear if he used the Force as well).
  3. Against Admiral Motti on the Death Star in Episode IV.
  4. Against Admiral Ozzel at Hoth in Episode V.
  5. Against Captain Needa after his failure to capture the Millennium Falcon in Episode V.

As the linked Youtube video confirms, Vader never lifted anyone off the ground when using Force Choke in the films.

That said, Dooku lifted Obi-Wan off the ground when choking him in Episode III:

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The concept of lifting a person off the ground when choking him/her did come before the prequel trilogy. For example, some (now Legends) video games have a dark side power (sometimes called Force Grip) in which the target is lifted off the ground. For example, from Jedi Knight II: Jedi Outcast:

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This is probably where the idea of a levitating Force Choke originated from. The games were probably inspired by Vader's first use of Force Choke in Episode IV, in which he also lifted the target off the ground (albeit physically), or as a combination of normal levitation (of lightsabers, X-Wings, etc.) using the Force and Force Choke.