better for what? If you are intending buying shares, then the market value is relevant. If you are making a judgement about the future of the company then the book value is relevant taken into account with other factors like management, products, visibility etc.
The reply to the query depends on who you are. If you are a buyer of the company, then book value tempered by the market value will be relevant; for market value reflects the view of the market on the value of the company and its products. If you are an investor, book value will be relevant. But then, market value reflects anticipations, projections of profitability of the business.