What are the six biggest spanish speaking countries in 2010?

You're asking for the six largest Spanish-speaking countries by population in 2010. Here's the list:

1. Mexico: 112.3 million

2. Colombia: 45.2 million

3. Argentina: 40.1 million

4. Spain: 46.8 million

5. Peru: 29.5 million

6. Venezuela: 28.4 million

Please note that while Spain is technically on this list, it's important to remember that Spain's primary language is Castilian, a dialect of Spanish.