Gambler - We all know why....
Ronin - For all the energy he puts on here, in his posts (which are really awesome), the cool Apocalypse rpg and of course for bringing back the fabled Zero Squad back to life. Not to mention he is a cool guy and he took part in one of the most emotional rpgs that I have ever seen (Soldier's fate, just read his blog. I know I was also in it but I was certainly outclassed)
Number three is hard. Arrow (with all of his accounts) is a fantastic writer but I rather go for Kurrent because he leads one of the major teams on here, is in almost every rpg, writes interesting posts (not as good as Arrow's but whose are?) and probably does the most surveys on the Vine. His presence is to be felt everywhere.
I don't know why no females are on my list but as it seems the guys are the ones that care more about the Vine (girls, we need to change that!)