The Twelfth Doctor

He arrives brusque and bewildered, unsure of his own face, asking Clara whether he's a good man rather than assuming it. Older, sharper-tongued than his predecessor, he has no patience for social niceties, wields a guitar and sunglasses like armour, and treats kindness as something to be worked out rather than felt.

Capaldi plays the alien strangeness first and the warmth second, so every scrap of tenderness feels earned rather than given. The scripts let him be genuinely rude, genuinely unsure, genuinely funny in a caustic register no era had tried before, and he commits to all three without softening the edges for likability.