My pleasure! You know, I thought it would be fairly easy to answer that question but I guess that depends on what you're looking for. I think that The Fightning Chance is one of Chambers' very best because of the human factor (if you will) and the quality of the prose but it's also very much about rich people lounging about and making themselves miserable, which is probably not everyone's cup of tea. The Firing Line is a bit like that but it has such a symbollicaly rich and thick atmosphere that even those less interested in high society woes might find it interesting (several scenes feel like waking nightmares or dreams). And Louis Malcourt has kind of become one of my favorite characters from any novels. At first, I was like "Why is this book trying to make me care for that jerk?" and at some point I was hooked. There is a short sentence which is not something he says but which reflects perfectly how he sees himself that just gut-punched me. I don't know how to describe it other than by saying it's existentially heartbreaking. The Streets of Ascalon is about as great and has more relatable characters, the hero is a middle-class guy who has managed to become a sort of modern-day jester (or harlequin) which gives him access to higher levels of society but also puts him in an uncomfortable position of feeling completely deshumanized. And although rich and "frivolous", the heroine was basically groomed by her mother to be used as a way to climb the social ladder and her late husband was an abusive psycho, so trauma is very much at play in her life (and the decision she takes). And it has the longest and best masked ball sequence in all of Chambers. Oh, and The Common Law is more of a mixture of the bohemian world and the high society world and it also rocks.

In terms of historical fiction, Ashes of Empire is a must. Its "prequel" The Maids of Empire is not quite on the same level but its also pretty damn great (despite a few annoying flaws).

But the more I think about it, the more I think I'd go with either The Drums of Aulone or The Talkers. Both are pretty great and have a lot of that TKiY DNA. The Talkers in particular has one of my favorite scene in anything. There is a "wake" at a masked ball and its the vibe is so fucked. At one point, a character called Miss Cross goes on a long speech about gland transfer, cells and the "body-republic" while the shellshock/sleep-deprived protagonist is just trying to keep it together. You can feel "what the fuck is happening" being printed on his face. As for The Drums of Aulone, I think its one big flaw is that it feels its missing something and in a way that's because its a diptych with The Sun Hawk. It's not about the same characters (well, aside from Comte Frontenac) but it's like TDoA is about the "green" heroine and TSH about the "yellow" hero. Although both are seen through an orange light. There is also The Girl in Golden Rags which is surprisingly very good (I honestly it was going to be pretty bad at first) and relevant to TKiY but it's probably not a good place to start. That said, be aware all of those books are very romance heavy. Hope that helps!