Not sure about the exact range, but the highest score I've ever heard was about 269 or 270. 179 was passing this year, not sure how low the score goes. 215 average, 20 points standard deviation.
My bad - 179 was passing last year, not this year. As for what a good score would be, it obviously depends on the specialty. I don't think there's any specialty where a 235 will completely rule you out. There's always a range of scores in every specialty, but that should be at least about average in every specialty.
i think that even most specialties have lower cut off points than that to look at people. for instance, the average step I of neurosurg people who match is about 226, if i remember correctly. the highest matched average (that is published) is in ENT with a 236. look at SFmatch for all the stats since they have a couple of the competitive matches.
I agree that most specialties have a lower average; I was looking at the ENT average when I said that 235 would be good enough for almost everything. If you want to go into a small FP or Psych program, just passing is fine. Top programs, especially in hard specialties, need much higher scores.