Transcending the real and the fake, Lemony Snicket narrates the entire series. As a character, he appears bothered and apprehensive in his narration style, and has an entire backstory of his own that's worthy of its own series (including falling in love with the Baudelaire children's mother and false murder convictions). While American, we always appreciate a good timeworn British narrator, and thus nominate Jeremy Irons.
Materialistic and greedy, the high-fashion Esmé Squalor is another antagonist who also happens to be Count Olaf's girlfriend. Although possessing many villainous tendencies, she's not as profoundly evil as her boyfriend, and later breaks up with him because of it. We'd like to see Emily Mortimer don an American accent for the mischievous role.
Tall, lanky, plagued by poor hygiene, and with a love for the stage, Count Olaf is the main villain throughout the series. Olaf has his eyes on only one thing: to obtain the Baudelaire fortune, no matter what. He served as the children's guardian for a brief period of time—where he almost succeeded in tricking Violet into marrying him— efore his true antagonizing nature was unveiled. He then turned to using a copious amount of disguises and henchmen to get close to the children again, with varied results. We can't help but think of Adrien Brody for the wicked role. He recently showed his eccentrically naughty side in The Grand Budapest Hotel and can definitely pull off some grey hair and a unibrow.
A few years younger than Violet, Klaus Baudelaire is a major bookworm who devours literature and loves to conduct research about anything and everything. Having a borderline photographic and astute memory, the knowledge he gained through his readings has helped the children escape several dire situations. Liam James has a bookish quality to him that would translate well to the character.
As ineffective as he is dimwitted, Mr. Poe is the banker who was put in charge of the Baudelaire's fortune and guardianship. Characterized by his top hat and circular spectacles, he's oblivious to Count Olaf's disguises and never believes the children's stories about him. Casting Jeff Garlin would provide some much-needed comedic relief
Violet Baudelaire has some major grit—the oldest of the children, she's a teenager and the leader of the group. She's also a very talented inventor who has a natural penchant for creating items at a quick moment's notice to get out of dangerous situations. Not to mention, she acts as the new mother figure for her baby sister Sunny. Ella Purnell, who played a young Maleficent in Disney's 2014 film, would fit the role nicely. Their physical similarities are uncanny, and she has equal parts kind and determined qualities to her.