I have used to options both which keep my coffee hot well. I tend to put it in my bag instead of a bottle holder - adds another level of insulation as well.

1) a Kleen Kanteen insulated bottle (i have both a spill proof lid and a "drinking" lid for it)

2) A Contigo coffee mug - I generally swear by these for travel, etc. For biking I use on of the newer ones with the locking button to avoid accidental spills - I even frequently through it in my bag without worrying about it