I'm always hunting for the good 'Hamilton' stuff on there. Honestly, the best route isn't to search 'best' but to check which stories have the most comments and votes over a long time. Ones with updates over years that kept an audience are usually solid. For that era and vibe, I got hooked on 'Theodosia'—it's a Burr/Theodosia focus that fleshes out his early life. The writing actually feels period-appropriate without being stuffy. There's also 'To the Letter,' an Alex/Eliza slow-burn that nails the tension before the war.
Some of the modern AUs can be hit or miss, but 'Room Where It Happens' is a college AU that surprisingly works because the author understands the characters' ambitions and rivalries, just translated to a frat and student council setting. Avoid anything labeled 'smut' right off the bat unless that's all you want—the plot tends to be an afterthought. The real gems are often buried under less flashy titles, so I'd sort by 'Hot' in the Hamilton tag and scroll past the first few pages.