another vote for Durametric. the air bag lite was on and the dealer wanted to replace the computer, but the Durametric let me see that it was a seat belt switch instead.
Generic OBD II readers are ok for basic codes but that's about all. Durametric is the next step up and does all that and resets the airbag light but requires a laptop. The next rung up the ladder is a PST2 which does all of the above as well as real time monitoring, logging and the changing of other options and setup elements such as programming, cluster transfer etc. etc.