Is Guinness a beer first and foremost? Who is the book of world records named after? Does s/he deserve an entry? :-)
It depends on who you are and where you are from. If you say "Guinness" in the U.K. everyone will think of the beer first. Unless you are young, and can't get into pubs, in which case you will probably think of the records book first.
Yes, Guinness is a beer first. The Guinness book of records is named after the beer maker.