Eddie Redmayne for me, he's my go to inspiration for everything from my colour combinations to my hair.
It's funny, I used to be too stuffy to like the style of Tinie Tempah and the like (not helped by my dislike of his music), but I'm warming to that more individual, streetwear-ish aesthetic. I'd take it over Pierres Morgan any day.
Beckham gets the vote though for practical, actually wearable day-to-day stuff. He's made his fair share of style mistakes though over the years, as we all have.
David Walliams, love him or hate him is usually on point when it comes to dressing.