If you have to travel LAX-SYD in coach, try the QF lunchtime flight -- it's just as long, but more bearable as most of it's daytime. Plus you can just go to bed when you arrive in Sydney. My favourite hotel is (was? I heard it was being converted into apartments) the Sebel Townhouse in Elizabeth Bay (a bit out of the centre, but that means you can see more of Sydney, right)? Great service, all mod cons, and a rate of around A$180 per night including breakfast.