At first I was a little hesitant to give a serious reply to this thread, because after being the leader of the Cracco Clan for almost 8 years, my view would obviously be biased. But now that Chippie replied as well, I guess that means it's OK.

1.The most skilled clan: Cracco Clan
2.The most legendary clan: Cracco Clan (since the imperial march)
3.The clan who has contributed the most to jj2: Cracco Clan
4.The best behaving clan: no clans come to mind at the moment
5.The coolest clan: Cracco Clan
6.The winner of jj2WC: Dark Mercenaries
7.The winner of jj2WC2: Cracco Clan
8.The Winner of jj2WC3: Cracco Clan or 8th Dimension
9.The biggest clan: Cracco Clan
10.The most Polish clan: VersSus
11.The most active clan: Cracco Clan
12.The dead clan: Xtreme Dreambunnies (will always be in our heart <3)
13.The Nicest leader clan: Gurus of Proactive Warfare
14.The Nicest members clan: Cracco Clan
15.The Most jcf adminstrators clan: Dark Mercenaries