Well, my favorite faction is my own, the Consortium. Though, it simply hasn't been around or active long enough to make much of a diffrance in any other faction's RP, with the possible exception of the AFA. Though, I'm trying
As for more established factions, I think the LWB and RM interactions are among my favorites. While my LWB dosen't actually fight unless his friends are threatened, I do a LOT of spontaneous RP with the RM andI have to say that it's some of the best around.
LWB and Die Wilden RP is also quite enjoyable. In Udo's case it leads to a lot of mind-control and confusion, and at one point, romance...
We need to do more of the latter. For Udo is lonely... :(
I can say that I like the Golden Chrysanthemums as well, as my GC is becomming more fun a character to play. Though, we don't have the kind of consistant interaction as the LWB-RM. Good RP is sort of hard to come by in Kusari at the moment, as most of what I meet are a wall of unspeaking powertraders.
However, my interactions with the AFA and Hogosha have been quite enjoyable, as few and far between as they have been. Personally, I think more of them, and more Samura and Kishiro players should become active. To give Naomi something else to propagandize and eventually feed to Watsas for his meat-harvesting operations.
