That isn't just TW, but I have found that the best and most aggressive players are also often easy and pleasant to deal with.
I'm not sure I'd use best and most aggressive together, since I personally think the people that are recklessly aggressive are being held back by their aggression, but I'd agree with the best part.
Best is, of course, subjective, but the people I consider to be the best typically are the kind of players that if you were to be a new player and message them with a well written message asking them questions pertaining to the game they'd take the time to write back a well written response and do their best to attempt to answer the question.
There's a lot of people as well unfortunately who think they're on the same level, who I think would be more likely to respond with, "Lol, noob." or other similar drivel because they're less secure in their understanding of the game and feel to continue to succeed they need to hold back other people from improving.
I suspect many players fall in the same boat I do as well. That is to say: If you mail me and ask a question, I will do my best to answer it as completely as possible and without any sign of arrogance. On the other hand if you mail me boasting about how great you are, and how I should respect you, and I don't see it, I'm probably going to tell you so, and it might offend you.
On-topic: My least favorite players are cocky wannabe elites