Rugby League Live 4 was hands down the best Rugby game of either code ever made and it's not even close.  I've got over 200 hours of play on it.

It's the most fluid of any game, the passing, line running, defence, and kicking are excellent and the AI is actually challenging.

I've played every Rugby game ever made and none of them even compare.  I wish a Union game would take RLL4's engine and just run with it.