I changed Bob`s food to Burns brown rice and chicken a little while ago and he is doing really well on it. I chose it because it is a holistic natural food, also all Burns food is approved under the BUAV's new 'No Animal Testing' Pet Food Standard. (Here is a link to the BUAV site if you would like to know more http://www.helpthedogs.org/index_campaigns.html)

Burns is available online in the USA and Canada, and there is also a toll-free number for enquires. Here is the link if you want to check it out: Burns Pet Nutrition
As I live in the UK, I don`t know how it compares pricewise to the other foods in the USA but there is a link in there to the online shops, where you can check out price (includes shipping), and ingredients too.