Germanic would definitely be one of them, as this family gave rise to English and German as well as Scandinavian languages: Finnish, Norwegian, and Swedish, which occupy a large portion of the area of Europe.
Another language family would most likely be Slavic, because this gave rise to Bulgarian, Czech, and most importantly, Russian, which is literally the biggest country in existence.
Wow, I just realized that this question was asked LAST YEAR. This came up in my suggested questions, so sorry about the wait. I actually just joined up today. :)