No it is not. My favorite song by AC/DC is Back In Black. It is a lot more characteristic and unique song which has an epic guitar riff. Highway To Hell is also a great song, though.
Although Highway to Hell is a great song, AC/DC made many more great songs. Some examples are Big Balls,Back in Black and A Whole Lot Of Rosie. So pin pointing just one of their songs as great would be a very hard decision.