First of all i should admit that russian language is very rich. And probably it is very complex for non-native speakers. Because we can create new words without even realising it, simply by adding prefixes or suffixes to the word.
What is also amasing about this language, that there are almost no dialects in russian. People from different regions can simply understand each other.
And of course we shouldn't forget about our brilliant writers who developed and glorified our language.