Rocker

The live versions of Rocker in 1977 were the best...check out Live at Atlantic Studios and you'll see (hear) what I mean...
This one in 1978 is great as well:

This one is in 1981, Tokyo...not that I don't like Brian Johnson...he's a great lead singer still kickin ass at age 62...but being the replacement for Bon Scott has got to be the most ungrateful job on earth.
He does a great job singing Bon's song: