Again this is really hard to nail.. HOWEVER
If You Want Blood.. is by far my favourite album EVER by anyone.
Back In Black remains one of my all time favourite albums as well as it came out when i was 16 and they were the first band I ever saw on that very tour.
Honourable mentions also to Powerage and Highway to Hell... that run of four albums has to be one of the strongest ever by any band
1º Let There Be Rock
2º High Voltage
3º Back in Black
4º Highway to Hell
Back in Black-is best!