RUGBY 2005 is a pretty decent game. It's a much higher quality game than RUGBY LEAGUE. The AI isn't as haphazard (like running across field, over the sideline and then throwing a 10 man cut out pass over his shoulder to a guy 2 metres in front of him who then proceeds to make a break, but passes to a heavily marked player who has 4 player gripping his waist, but manages to offload a pass 10 metres backwards to a guy who runs backwards for a short while who then runs in a forward direction, but looks as though he's running backwards and then steps no-one, but all my defenders have to vacate the area because there was a scrited step and then runs all the way to the tryline only to end up diving over the deadball line) and the momentum in tackles is handled well. The tackles aren't as scripted as LEAGUE (like catching someone from behind, but smashing them front-on) and the passing game is fluid (though you can only cut out one player, I think).
Fast players are fast even on hard (unlike LEAGUE) and each player feels like an individual because they're rated out of 100 rather than 10 (which doesn't allow for many variables). It has a good replay system too, which is very important. I also like the fact that you don't need to press a button to tackle, unless you need to dive.
On the downside, it lacks stats (so I don't bother playing it very often) and the difficulty levels aren't very well worked out. Medium is incredibly easy (150-0 in 20 minute games is quite common) and hard is damn hard (for me anyway). The kicking game is crap too. It's also a rugby game, so on hard, you have to play almost as negatively as the real players do.