What is the most famous company today?

Probably Microsoft

according to marshallindex.com which tracks the popularity of words in more then 12.000 Media, its:

1-Toyota

2-BP

3-Shell

4-VW

5-Verizon

6-Mitsubishi

the whole list is here:

http://marshallindex.com/term_lists/25-forbes-global-200?order=average_desc