All victims are listed in alphabetical order. My ancestors all left France before the guillotine was first used in France in 1791. However, I was able to find a few victims listed with the same surnames. Perhaps they were distant cousins although I doubt if I'll ever know for sure.
I found the list of victims easy to use even though the site is in French. If that isn't one of your better languages, use the Google language translation tools at http://www.google.com/language_tools or a similar translation tool elsewhere to make the translations for you. The online translation tools often create awkward text but generally are readable.
The list of victims of the guillotine can be found at: http://les.guillotines.free.fr.