I've tried a lot of travel mugs, and I've been disappointed in almost all of them. They're either too complicated to use, they leak, or they're simply no good at keeping beverages warm. The Zojirushi doesn't try to be anything that it isn't. It's simply a basic thermos that keeps beverages warm (or cold) incredibly well.
There's no fancy pop tops or sipping spouts here. Just a screw off top, and a wide mouth container. But the truth is, you may not want or need any more than that. I find that I make coffee in the morning, pour into the Zojirushi, and pour into a real mug once I get to work. The beauty of this thing is that it will keep your drink at 156°F for 6 full hours. It's incredible to screw the lid off hours later and see steam coming out of the mug.
It's also leak proof, and damn sturdy too. I've dropped it several times onto concrete over the course of the year or so that I've owned it and it looks like-new and functions as well as it did when it was brand new. It's available in black, blue, pink, or champagne.