When ratings column was there, as far as I remember this was the higher rated talk: https://www.ted.com/talks/ken_robinson_says_schools_kill_cre...

And the lowest rated one, I cant find it, but the presenter made a put with word "shit" in it or something like that and kept repeating to get a few more laughs out of the crowd, but he kept doing it (4-5 times in a span of 4 min), he stopped when Chris Andreson lost it and spoke up from the audience saying he won't ever present on that stage again.