Man, 'The Godfather' is still the gold standard for a reason, but if you want something that moves faster, Dennis Lehane's 'Live by Night' is phenomenal. It’s a prohibition-era epic that just never lets up, hitting you with family obligation, violent ambition, and that terrible sense that a character's choices are boxing them in. The tension between the lead and his mob boss father-in-law is a slow-burn fuse that makes the final explosions feel inevitable.
For something more modern and absolutely vicious, check out Don Winslow’s 'The Power of the Dog' trilogy. It’s not just mobsters—it’s the collision of cartels, the DEA, and corrupt governments over decades. The scale is huge, and the violence is brutally matter-of-fact, which somehow makes it hit harder. I finished the last book feeling like I needed to sit quietly for an hour, it was that intense.