Anya, only once. When she wanted to become human again, after turning back into a Vengeance demon again. She wasn't given an option to be "good". She was forced to live a human life after her necklace was broken by Giles. It wasn't for her to choose.
She was proficient at magic, she could have gone done the black arts route and made a name for herself as a powerful black witch. She could have left Sunnydale and never looked back. Instead she CHOSE to stay with Xander and Buffy and be a part of the white hats.
Spike was forced into it by the chip, his soul, and his love for Buffy. He wasn't given a choice. It just happened. He didn't choose to be "good" and got his soul back. He wanted his soul back so Buffy would like him. He figured, that's what he didn't have but Angel had. It was never about being "good". It was more like "I'll do this so that Buffy will like me".
He could have left. Could have found someone to get the chip out, used influence as William the Bloody, but he didn't even look for anyone to do that past S5. He could have gone back to Drusilla and it would have been her turn to look after him, she was willing to accept him. Instead he CHOSE to stay in Sunnydale, with Buffy and be a part of the white hats.
Angel was given a choice by Whistler, to be good. But he already was "good" ever since he got his soul and broke away from Darla, Spike, and Drusilla. Besides, he was cursed. He wasn't given a choice.
Just because he had a soul doesn't automatically make him 'good'. Charles Manson has a soul. Ted Bundy had a soul. That's not an argument. Angel CHOSE to help Buffy, CHOSE to go to LA and help the helpless.
Faith was also forced into being good by Angel and Buffy. It was never her choice. Her choice was to go to jail to reflect, not to be "good".
Faith turned herself in. She could have run. She could have killed Wesley, then Angel and left, never to be seen again. She could have broken out of jail countless times before she did in 'Release'. Instead she CHOSE to pay for her crimes by staying in jail, she CHOSE to go back to her Calling and Slaying.
Connor wasn't given a choice either. He was sent to a Hell Dimension, manipulated by Holtz, and memory edited.
Connor, I'll give you. He was kidnapped and brainwashed. But he thought he was doing what was right, but we, as viewers, or at least some of you who aren't me, saw his the bad guy.
Harmony was given a job, and was forced by Angel's new rule about not drinking human blood. She was forced. Not her choice.
No one forced her to work at W&H. She could have left anytime she wanted. Instead she CHOSE to stay and adhere to the 'no human blood' policy and work for the white hats.
Lindsey on the other hand, was given a choice by Holland Manners. And another choice by Angel. Notice how he wasn't forced to do any of his choices or had to fight for them. It was just handed to him. No other character were ever just given redemption that easily.
Willow, after killing someone in cold blood and trying to end the world because of her grief, was welcomed back with open arms and without a word being said about what she did. Her friends gave her a second chance to be good without question. How is this not an easy shot at redemption?