The best economy no frills computer that gets the job done? What job? Do you need nitrox? Do you want an air-integrated computer? Since you said no frills, I guess that's "no" on both. Genesis Resource or Oceanic Versa are good; around $200 online, and I believe both are made by Pelagic. Rodale's just recommended the Resource as an entry-level computer.
Also, do you prefer a wrist mount, or console? Do you plan on getting into more technical diving in the future? Do you want this computer to last you a while? If so, the Suunto Vyper is about $100 (est) more than the others, but adds nitrox capabilities, and can be used in gauge mode.