Yep - in my office, we have a regular rotation of staff from interstate and the rivalry battles about football codes can be quite entertaining.I don't think it's worth getting into the AFL versus NRL battle, because it could get ugly.
I personally have never gotten into the AFL - although I did find it easier to watch on a widescreen TV, so I guess being at the game would make even more sense.
I think it is easier for me to watch rugby league, having grown up with it and with a local team to support. Following a team called "Sydney" in the AFL doesn't give rise to the same tribal passions...