Obi-Wan cuts off Zam Wesell's hand.
Why? She was about to shoot him.
Where? At the wrist.
No! Where? A bar on Coruscant.
With What? Lightsabre.
Did it bleed? No.
Prosthetic? No, she died soon after.

Dooku cuts off Anakin's hand.
Why? They were fighting.
Where? At the elbow.
No! Where? A hanger on Geonosis.
With What? Lightsabre.
Did it bleed? No.
Prosthetic? Yes, a gold metal one.

Obi-Wan cuts off Ponda Baba's hand.
Why? To protect Luke.
Where? At the elbow.
No! Where? Mos Eisley cantina.
With What? Lightsabre.
Did it bleed? Yes.
Prosthetic? Probably.

Luke cuts of the wampa's hand.
Why? So the wampa won't eat him.
Where? At the shoulder.
No! Where? In the wampa's cave.
With What? Lightsabre.
Did it bleed? Yes.
Prosthetic? Probably not.

Vader cuts off Luke's hand.
Why? To try to get Luke to turn to the Dark Side.
Where? At the wrist.
No! Where? Under Cloud City.
With What? Lightsabre.
Did it bleed? No.
Prosthetic? Yes, a nice one with artificle nerve endings, and it looks real.

Luke cuts off Vader's hand.
Why? Vader was talking about Leia turning to the Dark Side.
Where? At the wrist.
No! Where? In the Second Death Star Emperor's throne room.
With What? Lightsabre.
Did it bleed? No.
Prosthetic? It was already a prosthetic when Luke cut it off, and since Vader died soon after, he didn't get a new one.