It's hard for me to make a top 10 of all players. Besides I can't rate a lot of people because;
1. In order to find out if you're the best players, you have to have played against all other JJ2ers (both solo and teamplay combinations),
2. Everybody has his own gametype he is better in than in other gametypes, and even levels in which he's better than others.

I think BunnyElmer, Stiletto, Jippo and myself are some of the better players though, CTF-wise. And when it comes to how much you are online, well it also depends a lot on which timezone you live in. Since I semi-stopped playing in RO and I fully focuss on JJ2, I am on Jj2 a lot. Mostly in private training sessions of CC, or in trainings of my allies XSD and BOD.