Its not really my cup of tea if i'm going to be honest with you. It gets really reptitive after a while and isn't all that fun. Now, some really good storys can come out of it yeah, I just overall don't really think its that fun. I've participated in one in a seperate forum, it was just sorta "meh".
Lol all of them. I actually pretty sheitty at mafia if you look at it closely enough. But overall i'd probably say DA:I mafia since it was my first game.