The Zojirushi Stainless Steel Mug is a simple but incredible travel mug. It's got a smooth stainless steel finish, a wide mouth opening, and a double-walled body.
The pieces are easy to remove and clean (unlike other popular brands), and it has a very tight fitting lid that won't spill when closed.
Nearly 5,700 people on Amazon have given the mug a stellar 4.7 out of 5 stars, so you know you've got a solid product on your hands.