Traditionally, death is cheap in roleplaying games. Characters die all the time.

And if PC deaths are a dime a dozen, NPC deaths go for about two gross a penny.

So to make a character's death have an impact, you need to do something special. Have it happen to a character who's been an integral part of the scenery of the campaign. Someone the PCs interact with frequently, and get to know. Someone who is always there, helping out, and who they have helped out in return. Someone who the players have good reason to believe will always be there.

In other words, not someone who appeared for 10 minutes a whole movieadventure ago, and then just shows up again after not being seen for ages, and promptly dies a minute later. (An outstanding character roleplayer can cope with this, but those are about $50,000 a pop.)

Transcript

Anakin: You told me there was still a bounty on my head. Why?
Shmi: I didn't want you coming back. After what you did to Cliegg.
Anakin: But I did it all for you. I love you.
Shmi: Anakin... I... <cough>
Anakin: You love me too, right? I'm your son.
Shmi: You've changed so much.
Anakin: Tell me you love me!
Shmi: I... I... <cough> <hack> <wheeze>
Anakin: Mother!!! You can't die!!
{beat}
Anakin: {angry} They'll pay for this. They'll all pay.
{Anakin rampages through the camp, slaughtering Sand People}
[SFX]: Whooom!
[SFX]: Whooom!
[SFX]: Whooom!
[SFX]: Whooom!
Sand Person: Ow!! My splanch!