What anesthesia should I use for breast augmentation?

I always use general anesthesia for breast augmentation.  You should really be asleep for the procedre for your comfort and also so the surgeon can work more efficiently.  You are also sat up to make sure the implants are even.  Being asleep is better.

During breast augmentation, I prefer to use general anesthesia.  Patients are kept comfortable, and entirely relaxed during the procedure.   Because patients are typically healthy, there is no added risk to having patients completely asleep with a general anesthetic. 

Since I own my own surgicenter, I have a complete control over who my anesthesiologist is. I use exclusively MD anesthesiologists. Incredibly enough, it is hard to find an MD anesthesiologist who is proficient at Sedation anesthesia.
I myself had to learn how to use local anesthetics in an efficient and comprehensive way so as to minimize the amount of sedation given. A good team proficient in the technique will give you:
1) Great analgesia during surgery- you will not feel anything
2) Amnesia- I have yet, in a year and a half of using exclusively sedation for breast augs, have a patient tell me they remembered anything. As a matter of fact, it is EASIER for a patient to get "light" during general anesthesia (while paralyzed with a tube down their throat) and remember stuff, than it is for a sedated patient with an anesthesiologist competent in sedation techniques. The reason is that during sedation the anesthesiologist will be better able to see and monitor the patient getting light than during general anesthesia.
3) Better analgesia AFTER surgery- Because the nerves were anesthetized BEFORE surgical injury, and because of the greater reliance on longer acting local anesthetics, the patient has less pain after surgery. There is plenty of experimental evidence backing this up.
Sedation gets a bad rep because many MD anesthesiologists learn mostly General anesthesia during their residency and don't feel comfortable with sedation. Sedation is harder and requires more concentration to find the "sweet spot". An MD anesthesiologist not proficient with sedation techniques takes the patient on a roller coaster ride where sometimes the patient is too light, then he overreacts and overmedicates and you find yourself struggling to keep the patient's airway open. An MD anesthesiologist proficient in Sedation techniques gives the patient a smooth ride and the airway is never in question.
I did Breast Aug with General anesthesia for many years, and the best testimonials come from patients who have had both types performed. There is no question they prefer sedation. I will never go back to general anesthesia. In longer cases General Anesthesia has higher risks of pulmonary embolus and pulmonary complications, and in all cases, patients feel much worse after surgery. If it was my daughter, or wife, (or even me!), sedation is the way to go.