Heh, fighting is not my forte... speaking my mind is, however...
In the LOTR, I felt that the best person draw sword with would be Aragorn... since he would probably be king anyway, and would probably reward anyone who he deems heroic...
It is probably a bad idea to fight alongside Sauron or Saruman because they won't give a fiddlestick about who are their allies.
In Silmarillion, it is probably a bad idea to fight alongside any faction at all... except for Eonwe, the Herald of Manwe.
The reason for this is that, almost all factions loose out in the end, and the only ones who finally benefited are the Numenoreans, who are supposed to represent the men who joined Eonwe...
In the Hobbit, the obvious thing to do would be to fight the orcs and share the treasure!
