who is the best proplay

If I had to go off of this season and based on the number of games and success with the champion, it'd probably be Darshan currently. There's only but so few that have picked and looked good on it (Vizicsacsi and TheShy being two others I've witnessed)

All time however, we need to go further back. A Korean player definitely holds that title. I would believe it to be Ssumday or Huni but I won't confirm that as fact.

Marin/Smeb/Huni/Ssumday/Khan, thats about it.