We faced the same problem in a University project and were able to solve it using
We quite enjoyed the capabilities of this tool on the command line. We also called it using python code to render the current state of webpages. It has the option to deliver the webpage as pdf, usually not perfect to preserve the website view due to the Page formatting (A4 for example), or as png (preserves the view of the page but not links)
There is also the readability(for Python:pypi.python.org/pypi/readability-lxml) project we used that does the ads removal and content detection quite well (e.g. for newspaper articles and the like). If you just want an addon or extension for your browser the following readability implementation might satisfy your need: