Oh, Sid. He’s just insane,isn’t he?
As you probably know, Sid is that sadistic kid who blows up toys for fun in Toy Story. He’s the complete opposite of sweet, caring Andy and that means he’s Woody’s worst nightmare and the perfect foe for him. During most of the movie, Sid is just a threat lurking in the background, blowing up Combat Carls. Then Woody and Buzz end up at his place, surrounded by creepy toys who are probably cannibals. And, of course, the knowledge that should they fail to escape, Sid will blow them up for fun.

Memorable
In one of the most memorable scripts Pixar has ever produced, Sid is a strong presence and has some fun quotes himself (“No-one has ever attempted a double bypass brain transplant before!”). If you think about it, the average fan probably remembers Sid more than Andy, simply because Sid is a an insane, super-fun villain to hate. I’ve had countless people talk to me about the way Sid sleeps, for example. That’s leaving a mark in the audience.
And the thing is, Sid simply has a lot of fun being evil. I haven’t seen Toy Story in a while but I perfectly remember him jumping on top of one of the Pizza Plant games laughing maniacally. Sid doesn’t have a lot of screentime but he steals the scenes he’s in.

Punished
I have to admit, half the fun watching Sid is knowing he’s going to get what’s coming to him. Imagine your hobby is torturing toys and suddenly discover toys are alive and crawling out of the mud and jeesh, that’s a good scene. It’s a lot of fun to see a villain realize he’s wrong and get punished for it. After seeing how he mutilates, deforms and destroys so many toys it’s impossible not to enjoy all the emotional trauma the toys must be inflicting upon him.
And ultimately, if you enjoy someone being beaten, traumatized or even killed that means they did their job as villains very well indeed. Sid is the kind of bad guy you hate to love but you simply love seeing him get his comeuppance. The only way we’d all forgive Sid is if he had found Lotso in Toy Story 3 and gone back to his crazy ways.