I agree with Jim that it's pretty subjective.
However, I can't say that I fully agree with Jim's thought that "success rate" is a big determining factor. While I agree that success rate is important, there are people on the Forum who had their surgery done at what is supposed to be the biggest and best place for AN surgery, yet their surgery wasn't nearly as successful as some of us who had our surgery done elsewhere.
A lot of what determines success is based on the size and location of the tumor and unfortunately sometimes just plain old luck.
I also feel that it's very important to like your doctor - in addition to having the utmost faith, trust, and confidence in him/her.
Searching the Forum for your doctor's name is a good idea, but keep in mind that not all AN patients participate in the Forum - and the majority of those who do on a long-term basis tend to be people who have had "issues" that they are trying to research and resolve.
You might want to check out the main page of this website - the physicians/facilities section. The ANA doesn't endorse docs or facilities, but they do list Centers of Excellence - which means the doc(s)/facilities meet a pretty stringent set of guidelines/rules set down by the ANA.
Best,
Jan