I'm a big fan of "turtleneck's" or whatever the name is, as there's a lot of different expressions with the same meaning. What I like on them is the versatility the style gives as there's many many ways to combine it from casual to formal, always confering an added value to an outfit. Usually I prefer these styles shown on the pictures below and wear it with a blazer or just leather jacket for a more casual outfit. It goes also well as an outwear garment when it's a more heavy material, also quite trendy these days.
Elegance and timeless are the key elements to make it a must-have every autumn-winter season.
The Sartorialist
Trendy Crew
Iconic Street Style (I dont quite like this outfit combination, but the full-black effect captured my attention).