What anesthesia is the safest that still works?

All are safe . When used appropriately. All types can also have complications. The discussion as to what is the best anesthesia for you depends on your health status and the type of surgery you are having.
Expertise. In the hands of experienced and well trained anesthesiologist any type of anesthesia is very safe. Board certification confirms that anesthesiologist met certain learning criteria. Always discuss with anesthesiologist your options: general, regional or sedation. Anesthesiologist is your best guide.
Depends on need. Anesthetics are tailored to the needs of the patient and the needs of the surgeon. Hence the safest anesthetic for a bunion is not the same as the safest anesthetic for a cardiac surgery. Please get in touch with me or one of my colleagues if we can answer a specific question .