Alas, Poor Scrappy: Drawlight. He's a thoroughly unlikable character with no redeeming features, but his violent, unknown death alone in a forest evokes pity all the same.
Even more so in the TV series, where he's eminently more pitiable.
Crazy Awesome: Strange, once he intentionally drives himself mad, with emphasis on both the 'crazy' and the 'awesome'.
Ho Yay: Some of the gentleman's interactions with Stephen could be interpreted as this.
Childermass and Mr. Norrell bicker like an old married couple on occasion (with Childermass obviously overstepping his bounds as a servant, and Mr. Norrell barely noticing). In the book, Mr. Norrell is noted to be relatively comfortable with homosexuality as long as it doesn't interfere with the study of magic.
Jerkass Woobie: Mr Norrell, a man set for a very public destiny but is wholly unsuited for it.
Moral Event Horizon: Crossed by Lascelles when he shoots Drawlight. While Drawlight may not earn much sympathy, his murder is so cold-blooded and unexpected that you know Lascelles has gone off the deep end.
Narm: Stephen Black using English magic to defeat the gentleman in the BBC finale. It was a bit-over-acted, the effects on his voice were ridiculous, and the gentleman appears to be so transfixed he does nothing to defend himself (in contrast to his stubborn book counterpart.
Nightmare Fuel: What happens to Lascelles. He's a horrible person who made the enmity between Strange and Norrell far worse, killed Drawlight in cold blood, and disfigured Childermass all for little reasons beyond profit and his pride. But he's also 'compelled' into taking the role of the Champion of the Castle of the Plucked Eye and Heart (probably along with having his mind wiped to fulfill the role's purpose) until someone kills him in turn. How long will that be?
The Neapolitan soldiers that Strange resurrects. They're mutilated and decomposing, and spend all their time trying to find Strange to beg him to put them to a final rest, or send them home to their loved ones instead of Hell. In the end Wellington orders them to be burnt, though who knows if even that released them? (Frustratingly, a footnote informs us that the "life" of such corpses can be ended by simply cutting off their eyes, tongue, and heart - but Strange never manages to figure that out.)
Older Than They Think: The story of John Uskglass has some resemblance to an English chapbook, The Merry Pranks of Robin Goodfellow. In the story, Robin (aka Puck) is a Half-Human Hybrid child of Oberon whose father grants him magical powers and gives the promise of eventually holding a kingdom in Faerie. Uskglass is admittedly human by birth, but was a foster-son of Oberon.
Spoiled by the Format: The book starts with a John Segundus trying to revive English magic and getting in contact with the reclusive Mr. Norrell, partnering with Mr. Honeyfoot. While the reader may think that Segundus will become Strange, it's certain that Honeyfoot's supposition that "Honeyfoot and Segundus" will revive English magic won't work out, given the book's title.
Visual Effects of Awesome: The BBC series has been praised for its use of special effects, putting on good spectacle while avoiding using it superfluously at the expense of character. The Miracle of York and Horse Sand were particularly praised by critics, but Strange's roads and The King's Road are also impressive.
The Woobie: Stephen Black. The Gentleman went looking for a woobie and ended up making one.
One of the footnotes gives us the story of the fairy called Buckler, who managed to lure several of the family members, servants, and neighbours of Simon Bloodworth into a magical cupboard from which they did not return. Two hundred years later Martin Pale is visiting a castle in Faerie and encounters a starved-looking little human girl.
”She said her name was Anne Bloodworth and she had been in Faerie, she thought, about two weeks. She had been given work to do washing a great pile of dirty pots. She said she had been washing them steadily since she arrived and when she was finished she would go home to see her parents and her sisters. She thought she would be finished in a day or two.”
Also, Lady Pole. She starts off as an Ill Girl whose mother hates the doctors and won't let them see her, and dies shortly after her introduction. Then, she is resurrected only to be enslaved by the Gentleman, and spends several following years sad and alone, unable to free herself from his enchantment or tell someone about it. And everyone she knows (except Stephen) thinks she's insane.