I have visited Ottawa countless times and now live near the ByWard Market. When friends and family come to town, Khao Thai is a must for dinner.
The red curry, tom kha gai, and pad thai are crowd pleasers. Service is also timely and polite, whether ordering in or taking out.
Don't listen any negative reviews - if you're in the Market and hankering for Thai, this is the place to be. A true gem!