Is Trader Joe's cat food okay?

I know the giant bag of Purina Cat Chow is not very nutritious, and the SPCA said that Purina One, which they gave me, isn't either. How much do I have to spend to get good cat food? I also give him 1/3 of a Friskies can twice a day. The SPCA said that if I went to a more nutritious dry food I wouldn't need the wet food, but he likes it so much that I would rather not discontinue. He also likes TJ cat food better than Cat Chow.