I use TLC
I've been using TLC since I got my dog - the breeder we got him from uses it, and recommended it. A major advantage is the home delivery - you can even set it up to deliver every x months, so you don't have to think about it at all. The food shows up at my house about a week before I would have run out of food.
Gwynn is always excited to see his food, and hasn't had any stomach problems. I stumbled across this post particularly because I wanted to check up on how my dog's food ranks, see if there were any major concerns with using it.