I prefer to play on the Allies side so I can use the M1. I will play Axis if the teams are uneven. I'll usually use the Mauser...until I can find myself an M1 on the ground, that is...heh heh.
I'm always axis unless the Allies need players. I just really hate the Allied weapons(with the exception of the M1). The StG is all I really need. Its accurate at range and has a great rate of fire.
I prefer to play Allied because I like the M1 but I always check the teams first and will join the Axis if they are outnumbered by 2 or more, in which case I use the STG of course .