Best level 6 unit.

I don't understand what exactly we're trying to figure out. There are many parameters, and they are ambiguous. "Best" means the strongest in the game? Or the most useful? Judging by the posts, many people are talking about strength! But what about usefulness? - Knights have speed, and when clearing the map, they can defeat more serious troops than Nagas and Dark Knights, which means more options to reach the desired artifacts or gold. They can be upgraded in separate stables (and they are often located frequently, which means you can save money in the early stages). Plus, they go first - who wouldn't agree that this is very important? They are not so inferior in power that their tactical advantages should be ignored.