I have an extensive collection of Guinness Book of Records'. It currently numbers 95 volumes including all 61 standard UK editions. (Numbers correct as of 1st January 2014).
It seems that whilst my collection is large, it is nowhere near as large and extensive as that of Martyn and Fran at http://guinness.book-of-records.info.
I am cataloguing my collection, and it seems most sensible to do it by country.
United States - 19 Volumes
French - 6 Volumes
German - 4 Volumes
Dutch - 3 Volumes
Danish - 1 Volume
Korean - 1 Volume
Greek - 1 Volume
Australian - 1 Volume
The following ones are not yet catalogued:
United Kingdom - 61 Volumes