Final project reports from 2012 Stanford Machine Learning class
cs229.stanford.edu
cs229.stanford.edu
Unfortunately, quality of papers and their readability highly depend on the skill of the author. There are some papers which are easy and entertaining to read because of the writing skill and effort put into it. Many though are not nice at all.
Here is an entertaining but serious one... http://www.cl.cam.ac.uk/~rja14/Papers/cocaine.pdf
http://cs229.stanford.edu/proj2012/ChangSaeta-AnalyzingCS229...
I just finished looking through both. They're both great if you're hoping to get some traction when it comes to learning ML.
(if it's supervised learning they use, I haven't read the paper)