Defendants who are represented by private counsel can save a bundle on attorneys' fees by accepting a plea bargain. It almost always takes more time and effort to bring a case to trial than to negotiate and handle a plea bargain.
Getting out of jail
Defendants who are held in custody -- who either do not have the right to bail or cannot afford bail, or who do not qualify for release on their own recognizance -- may get out of jail immediately following the judge's acceptance of a plea. Depending on the offense, the defendant may get out altogether, on probation, with or without some community service obligations. Or, the defendant may have to serve more time but will still get out much sooner than if he or she insisted on going to trial.
Resolving the matter quickly
A plea bargain provides resolution to the stress of being charged with a crime. Going to trial usually requires a much longer wait -- and causes much more stress -- than taking a plea bargain.
Having fewer or less-serious offenses on one's record
Pleading guilty or no contest in exchange for a reduction in the number of charges or the seriousness of the offense looks a lot better on a defendant's record than the convictions that might result following trial. This can be particularly important if the defendant is ever convicted in the future. For example, a second conviction for driving under the influence (DUI) may carry mandatory jail time, whereas if the first DUI offense had been bargained down to reckless driving, there may be no jail time for the "second" DUI