I've taken coffee to work for years (am partial to Harris-Teeter brand Hazelnut), mostly in 18 oz thermoses that LL Bean sells. I also use these for biking and walking in winter weather -- carrying them in backpacks. Coffee stays hot all day.

No leaks, ever.

http://www.llbean.com/llb/shop/48415?parentCategory=9007&feat=9007-tn&cat4=1099

My favorite larger thermos is one I bought at a Dunkin' Donuts in New Hampshire on vacation a few years back. It's stainless and has a nice DD logo-emblazoned rubber grip midway on the thermos.

No leakage.

This new vacuum bottle that Bean is carrying looks promising, but I don't have one to vouch for from experience.

http://www.llbean.com/llb/shop/64055?parentCategory=9007&feat=9007-tn&cat4=1099

Innate Kaze Stainless-Steel Vacuum Bottle, 450 ml
BPA-free stainless-steel vacuum bottle, ideal for hot or cold liquids


This next item is not a thermos, but an 8 oz flask and I love it for walking around. Great for shoulder bags or coat pocket. BPA-free stainless. I transport it inside a small neoprene bottle holder and it stays cold or hot for quite awhile. No leakage. It's not insulated so filled with hot coffee, grabbing it with bare hands will hurt. Fine with gloves.

http://www.llbean.com/llb/shop/64043?feat=sr&freeText=flask