These
Contigo Travel Mugs
I got mine in a two pack at Costco, but they are around.
*No leak or spills. You can put it in a gym bag, or whereever and they will not leak. The new ones have a locking button for double security.
*Really well insulated: they keep thing hot for hours. Really. You can put something hot in it, and hours later it will still be hot, not warm.
* Very durable.