Zojirushi SM-SA60BA Stainless Steel Vacuum Insulated Mug, 1 Count (Pack of 1), Black, 20 oz.

Why it's worth it

This 20-ounce vacuum mug keeps turning up at the top of insulated mug comparisons, and the reasons are all practical. It drinks like a mug and seals like a bottle, and the lid comes apart for cleaning without a fiddly push-button mechanism.

Heat retention is the reason to buy it. Lab testing published by Good Housekeeping found Zojirushi's vacuum mugs held liquid within a few degrees of their starting temperature after six hours, near the top of the group, and CNET's reporting on the brand's double-wall stainless construction points the same way. Coffee you pour before a commute is still genuinely hot at lunch, not lukewarm.

The lid is what separates it from a generic thermos. It's leakproof, so the mug goes in a bag next to a laptop without a plastic sleeve as insurance. One button flips it open with a single hand, which matters when you're driving or juggling a badge. And it unscrews into pieces you can actually rinse, unlike push-button mugs that grow a science experiment inside the mechanism.

From our review of 6 zojirushi kitchen products

What we like

• +Heat retention is the reason to buy it
• +The lid is what separates it from a generic thermos
• +The 20-ounce size is the practical middle

What to know

• –The insulation is almost too good