I'm going to go against the grain here and recommend MMO. 4 ounces per 10 gallons of gas in every tank, and no more. For best results, first run a tank of a good fuel system cleaner such as Redline, Regane, or Techron. When its time to fill up after the fuel cleaner has run its course, put the MMO in and run it every tank.
Its cheap and effective. The manufacturer also guarantees that when used in the fuel at the recommended dosage, that it will not harm injectors, sensors, etc.
-Spyder