Most recognizable opening riff...
 

Was in the car with the wife today and interstate love song came on and we started discussing recognizable guitar riffs. We then wondered what song ha the most recognizable opening riff ever.

We both came up with Sweet Child of Mine as tops. I thought Stairway is also up there with Crazy Train.

What are some others?

7 Nation Army

Satisfaction

I remember listening to a music historian on NPR saying that the main line from 7 Nations Army might be the piece of music from our era most likely to survive into the far future--long after we've forgotten the origin of it. He talked about its simplicity plus the fact that is has already spread around the world in various sports chants, etc.

He left out that it is fucking awesome, but that's certainly going to help.

Money for Nothing (if you dump the synth preamble)

First thing that popped into my head was Layla but 7 Nation Army probably has it beat.

It's impossible to argue against Seven Nation Army but Smoke on the Water was the first song I thought of.

I feel like half of AC/DC's songs could fall in here.

Still remember being a kid at the skating rink and every time "Hells Bells" would start, the old guy that ran the place would shout "Those damn bells!!".

I .. AM .. IRON .. MAN. With that nasty WHOOOAAAAAOOOOO on the guitar.

Also Sweet Child of Mine

Smoke On the Water would be one of the first (I still think about the Kids in the Hall devil skit - the holy trinity of rock!). You Really Got Me is another old one that benefits from Van Halen's update as well.

Back That Azz Up

Another one that is seared into my brain is Little Pink Houses. I grew up close enough to Fort Wayne, Indiana that I think I heard that song more often than the National Anthem growing up.

It's Smells Like Teen Spirit for me