Started with Doris Kearns Goodwin's "Leadership", which is a 4-in-1 biography of Lincoln, Teddy Roosevelt, FDR, and LBJ. I cannot recommend it highly enough! (Here's my more detailed write-up: https://terranostra.one/posts/Review-Lessons-from-the-Presid...)

Then went on to Ron Chernow's "Washington" (another great book), and am currently on Jean Edward Smith's "FDR".

If you're interested in presidential biographies, have a look at this guy's page: https://bestpresidentialbios.com/