Ignore polls.....
Almost everyone at Cambridge loves their college and think theirs is the best. If there was only 16 colleges on the poll, it's very likely members of TSR who happened to vote in it went to one of those 16 colleges....
there're more than 12,000 undergraduates Cambridge. It's not too difficult to realise the polls like is not be trusted anyway.
And poll itself is meaningless because of the reason above
Read this, if you haven't yet.
http://www.undergraduate.study.cam.ac.uk/colleges/choosing-a-collegeChoosing a college is the least important thing in application to Cambridge.