I still havn't decided which carbohydrate source is best in a dog's food (rice seems to be the winner so far) but corn is not on my list. Corn is basically sugar and cellulose. And since dogs (and humans) can't digest cellulose, it has really no food value at all. I don't eat corn very much myself, I'm not going to give it to my dog.
And through looking at resources and other opinions and such, I don't think that having a 'meal' (ie chicken meal rather than whole chicken) is that bad. I just consider it a meat source and leave it at that.
A real basic check is to look at the first three ingredients. I prefer the first 2 to be a meat source and the 3rd can be a grain. I don't know if I've ever seen a kibble where the first 3 ingrdeiants were all meat, but I'd probably buy it.