I'm always searching for books where the conversations feel like a sport. That electric back-and-forth where characters are playing verbal chess is just the best. I'd argue a lot of classic mysteries nail this, but they're often pigeonholed as 'cozy'. Tana French's Dublin Murder Squad novels, especially 'The Likeness', have this incredible, tense, layered dialogue among the detectives that reveals so much about power and history. It's not just witty for wit's sake; it feels like a necessary weapon.
For something with a completely different rhythm, 'The Thursday Murder Club' by Richard Osman has a drier, more observational wit. The retirees in that book are constantly one-upping each other with understated, brilliant remarks. It’s less about rapier repartee and more about a lifetime of accumulated, sly insight. I find myself rereading passages just to enjoy the timing. The humor comes from character, not punchlines, which makes the dialogue feel genuinely sharp rather than scripted.