What brands of over-the-counter creams are most helpful, or most recommended by doctors, for dry skin eczema?

Depends: For true eczema, a steroid cream such as Cortaid 10 (hydrocortisone 1%) can be effective. Dryness, however, can be treated with multiple different creams. Eucerin and lubriderm are two effective emollients for dry skin conditions. I recommend wetting the skin first, patting it dry (but not completely dry), then putting on the eucerin or lubriderm. See you doctor, however, if not improving.

Ceramide creams: The molecular defect in eczema skin is in the proper generation of barriers. Ceramides are found to be deficient in eczema skin. In addition to topical steroids, i generally recommend applying a ceramide containing cream (cerave or cetaphil restoraderm) first, and then 'seal' it on top with a more moisturizing lotion such as eucerin original lotion, or aquaphor if you are very dry.