[Cronos]

I don’t think English is anywhere near the most complex language. That would be Hungarian (Magyar) or Finnish or Estonian.

Descriptive and richest? Nope. Latin, Sanskrit, Russian and Polish seem more descriptive to me and German with its merged words has tons more descriptiveness

[Verginius Rufus]

Finnish and Estonian (which belong to the same language family) have 15 cases. Hungarian (distantly related to those languages) has a lot but I don't know how many. All of them have a word for 100 borrowed from an Indo-European satem language. Evidently their remote ancestors didn't need to count to 100.

The Slavic languages can have as many as 7 or 8 cases. Latin has only 6 but the vocative is usually identical with the nominative. Ancient Greek had 5 but Modern Greek has reduced that to 3.

[JesusIsLord]

Descriptive and richest?

My understanding is that Greek does a much better job of being an accurate language. E.g., ancient Greek, unlike English, had multiple words to describe the concept of 'love', each with a distinct meaning and nuance. The most commonly discussed are: agápē, érōs, philía, storgē, philautía, and xenía.