From time to time, I check the score of my website through different grader tools, to find out what can I improve on it.
I thought it would be a good idea to share this list here:
Nibbler: http://nibbler.silktide.com/reports/www.webstein.net This nice tool is the best and most complete of all; it's limited to 5 pages per site, and also has a paid version
WooRank: http://www.woorank.com/en/www/webstein.net
Hubspot's MarketingGrader: http://marketing.grader.com/report/http://www.webstein.net Is more focused on marketing and social media, but does a great job overall.