I have flown biz on OZ a few times and once in coach. I would not fly OZ biz again unless they had a screaming deal or if it's really the best route and time-in-the-air is important. The food they served was very similar to what you get in coach just better presentation and sides/dessert. I don't drink much so that has little value for me (ok, I know it's worth a lot more to others). IFE was the same on the 777s that I was on so no difference there.

Both TG and SQ are great chocies but for the SIN-SYD route, I think you get the lie-flat beds in SQ biz/raffles class which is great. Don't know about TG. Food has always been great too and having the choice of Dom P or some other fancy bubbly when you board isn't such a bad thing. :-) The biz class lounge in SIN makes most of the lounges in the US look like roach motels.