I've been partial on the ~15oz mugs so would vote for the 14oz Ramber Mug w/ Magslider Lid
www.yeti.com
It doesn't fit in cupholders well but I've had cars/trucks with junky cup holders so am pretty accustomed to putting it between my legs. Which rarely but occasionally spectacularly gets me in trouble.

YETI Rambler 14 oz Stackable Mug with Magslider Lid
Unlike traditional camp mugs, this double-wall, vacuum-insulated body protects from hot or cold contents while keeping coffee, chili, or oatmeal nice and hot.

It doesn't fit in cupholders well but I've had cars/trucks with junky cup holders so am pretty accustomed to putting it between my legs. Which rarely but occasionally spectacularly gets me in trouble.