For me, 'righteous' carries a heavier, sharper bite than 'moral'. 'Moral' feels like the everyday baseline — what most people mean when they talk about right and wrong. By contrast, 'righteous' sounds almost judicial: it suggests not just correctness, but a kind of absolute certitude and sometimes even self-righteousness. That extra edge makes it feel stronger, more uncompromising.
I also think 'principled' and 'incorruptible' compete for that stronger slot depending on context. 'Principled' has stamina — it implies someone holds firm to a code even when it costs them. 'Incorruptible' reads almost heroic, like a character from a novel who can't be bought. Personally, I find 'righteous' the most forceful in everyday speech, while 'principled' wins when you want to emphasize steadiness rather than moral thunder. Either way, word choice colors how we judge people, and I tend to favor the quieter conviction of 'principled' over the loud righteousness of 'righteous'.