Okay, so it's not YA, but Tasha Alexander's mystery series featuring Lady Emily is excellent enough that I decided to break out of the genre to recommend it. Featuring a strong heroine with a penchant for sleuthing, antiquities, and breaking the constraints of Victorian society, this series is chock full of intrigue, romance, theft, murder, and waltzes. The first novel, And Only to Deceive, sets the stage when Lady Emily discovers the man she married to escape her mother's clutches was actually passionately in love with her. As she reveals that her husband was far more than he seemed, she realizes she's falling fast for him. The only problem? He's dead. And his murderer is dogging her every step. As she struggles to understand who she can and cannot trust, she crosses paths with the charming Mr. Hargreaves, the flippant Mr. Andrew Palmer, and the iconoclastic Madame du Lac, among many others.
Lady Emily's adventures are continued in several sequels, where more shocking scandals and suspicious deaths come to light. Giving away more of the plots of the second and third books would probably spoil too much, but they are certainly engrossing. I haven't read the fourth yet but am anxiously awaiting it!
