Logo's of companies for which I have verified evidence that they use knowledge graphs and ontologies in production. This list is (of course) incomplete.
From ivo@velitchkov.eu
1. For etc see case studies of Top Quadrant
2. For Voklswagen, Nokia, Daimler, Bosch, I couldn't find quickly an online resource but they are all clients of eccenca
3. I can't remember seeing , which are heavy RDF user. You can find them along many others on Stardog's customer page
4. Philips, CreditSuise etc at PoolParty customer page.
5. Taxonic is now implementing Asset Managemnt system based on RDF at Schihol Airport but you should ask Jan if they are fine to associate their logo with that
6. I saw the logo of the European Commission, but not of European Council (SPARQL: http://data.consilium.europa.eu/sparql ) and Publications Office (SPARQL: http://publications.europa.eu/webapi/rdf/sparql)