Blythe Wood Works cedar dog (and cat) houses are extremely well made and very well insulated. We chose a large duplex (houses 2 large dogs- 82, and 88 lbs) and added decking and a little heat pump which can also air condition in the summer (both options were available from the manufacturer). Custom fit mats, and hard as well as soft heated pads are also options available. The customer service is great and you can see pictures of all their products on their website: BlytheWoodWorks.com

Pros: easy to assemble, 11 configurations to choose from, lots of options

Cons: you need to add waterproof stain to the assembled product

If your going to leave your dog in a situation where they need a dog house (and I wish people wouldn't) you should at least have one that is well made and well insulated

Pros: well made

Cons: cost