As previously stated, there are thousands of options coming from the UK/Europe.
For cheaper fares try:
Vietnam Airlines (Qantas codeshare from Ho Chi Minh)
Egyptair (via Cairo and Singapore Changi)
Equ: A340-200, B777-200
KLM (very cheap now; via Amsterdam)
Garuda (ok,cheap. via Denpasar, Bangkok and Frankfurt)
Equ: A330-300, B747-400
For Intermediate fares try:
Lauda (excellent airline; via Kuala Lumpur and Vienna)
Olympic (good airline, via Bangkok and Athens)
Japan Airlines (excellent service, via Tokyo Narita Intl)
Equ: B747-200/300, MD11, B747-400
Ansett/All Nippon Airways (good,star alliance, via Osaka)
Gulf Air (ok servicesafety, via Singapore and Bharain)
For Top range airlines try:
Malaysia (superb service, via Kuala Lumpur)
Equ: B747-400, B777-200
Qantas/BA (excellent atmosphere, via Singapore)
Cathay Pacific (outstanding, via Hong Kong)
Equ: B747-400, A340-300
Singapore Airlines (one of the best, via Singapore)
Emirates ( best in the world, via Singapore and Dubai)
Air New Zealand (long trip, via Auckland and LAX)
Equ: B747-400, B767-300ER
Thai (warm, friendly, via Bangkok)
Equ: B747-400, B777-200/300
I hope this helps you greatly. These are a list of the best airlines servicing Australia from abroad. But beware, many of these flights terminate at Sydney and will require a connection to other captial cities, usually included in ticket price. There are many Australian domestic airlines servicing main cities. They all provide seamless connections with partner airline or through agreements. These airlines are:
Qantas: B767-200/300, B737-300/400, Bae146-100/200 and Dash 8-400.
Ansett: B767-200/300, B737-300, Bae146-200/300, A320-211
Impulse: B717-200, Beech 1900D
Virgin Blue: B737-400
I hope this helps!!
If you want my recommendation then for a short journey with good entertainment choose Qantas, Singapore, Emirates, Malaysia or Cathay.
If you want some adventure and ethnic flavour, try Egyptair, Gulf Air, Garuda or Olympic.
Dont be afraid to choose the Asian airlines. They all provide excellent standards and service in order to compete with each other.
Personally I am always most comfortable on Japan Airlines. They offer perfect service every time.
Hope this helps,
PS. I am flying to London with Egyptair in December,
I will post how they were after my arrival. I cant wait!!