thanks for the shout to www.TasteSpotting.com
there are two pretty comprehensive lists of food blogs that I use:
I usually check out Foodgawker.com or Tastespotting.com which is a picture guide of all different food blogs. Of course, this is just a selection of blogs, but the pictures can usually direct you to some of interest.
There is also Foodbuzz.com which I believe is a foodbloggers central website. I could be mistaken, but I see it on a lot of food blog sites.