John F. Kennedy
From top to bottom: Cohesive & Co, J.Crew, Riviera Club, Club Monaco & Burberry
Every guy shoot have a classic crewneck sweater in his closet, not those bulky ones from the 80's, but fitted like the rest of your wardrobe. Don't wear it in the gym, but wear it with a plaid shirt and a chino. By the way that little triangle under the collar had a function it was developed in the twenties for football players, the V-notch enabled the neckline to expand so shoulder pads could be worn underneath. (thanks to Details & GQ for the inspiration).