I'm from Ireland, now living in Melbourne and have family and friends in both countries. The people, I've found to be extremely friendly in both places. Although I earn more over here, my job is very similar to what it was like at home but it's takes me much longer travelling to work here. The weather, even in Melbourne wins hands down over Ireland. I love my life in Australia and I agree with Paul about finding the craic in both countries. Having said that though, I will eventually return home at some stage in my future, just don't know when yet!
Best of luck with whatever country you decide on.