The correct phrase is "pieces of furniture." This is the most commonly used and accepted way to refer to individual items within the category of furniture. For example, you might say, "The living room has several pieces of furniture, including a sofa, a coffee table, and two armchairs."

The phrase "items of furniture" is less common and can sound a bit awkward or overly formal in everyday conversation. However, it is not incorrect and can be used in more formal or technical contexts. For instance, in a legal document or a detailed inventory list, you might encounter "items of furniture."

In summary, "pieces of furniture" is the standard and preferred term, while "items of furniture" is less common but still acceptable in certain contexts.