...what 3 rock songs would be the greatest ever?

I was watching a YouTube video of Dave Grohl waxing lyrical about the first time he heard Soundgarden's "Blackhole Sun". He bumped into Chris Cornell who asked him and the other members of Nirvana if they wanted to hear their new record. He said that on first listen it was a gamechanger, it incorporated Beatleseque harmonies, a more mellow and surreal feel and he could see that they had written a perfect song, the song that would make them huge.

It got me thinking about the greatest rock songs of all time, in a list of 3, from any decade, what 3 rock songs would be the greatest ever?

Now I am 4 days into this question and I am struggling to even define the question. Is this a purely personal choice based upon what I like or is it to with what constitutes a classic rock track or what is influential or a mix of all 3? 

I put the question to some friends and there responses were varied, one came back with "Teenage Dirtbag", I suspect he was joking. Another was in the US and was stranded as he'd run out of "gas", whatever that is and his selection was eclectic.

Another came back with:

David Bowie - "Life on Mars"

Jane's Addiction - "Ted Just Admit It"

Alice in Chains - "Would"

Another selected:

Queen - "Brighton Rock"

The Who - "Baba O' Riley"

Led Zep - "Whole Lotta Love"

And I still can't even define the question!

So, another friend suggested top 3 rock tracks from the 70's, 80's and 90's and then see if that narrows down to the personal greatest 3 tracks ever, selecting one from each decade, plus a wildcard.

One came back with:

70's

Queen - "Brighton Rock"

The Who - "Baba O' Riley"

Bruce Springsteen - "Born to Run"

80's

Faith No More - "Epic"

Guns 'n' Roses - "Paradise City"

Jane's Addiction - "Ted Just Admit It"

90's

Motherlove Bone - "Chloe Dancer/Crown of Thorns"

Pearljam - "Alive"

Rage Against the Machine - "Killing in the Name of"

Another:

70's

T-Rex - "20th Century Boy"

Led Zep - "Black Dog"

David Bowie - "Life on Mars"

80's

Guns 'n' Roses - "Welcome to the Jungle"

Metallica - "Battery"

Jane's Addiction - "Ted Just Admit It"

90's

Alice in Chains - "Would"

Soundgarden - "Fell on Black Days"

Stone Temple Pilots - "Crackerman"

I'm struggling with this because it genuinely isn't what's on the list, it's what is left off. Lynyrd Skynyrd, "Freebird" or "Sweet Home Alabama" deserve to be on any list of rock's greatest songs but then so does T-Rex "Get It On" or "Children of the Revolution" or Slade or the Sweet or Iggy Pop or the Stooges or the Damned or the Sex Pistols, all of these bands and many more that I love and adore (Thin Lizzy, UFO and Judas Priest!) all deserve to be on the list. I had to make the list based on merits and I based it upon songs that I love, bands that should be included because of what they are and what they achieved.

So, 4 days of thinks and I've managed the first 3 names for the 70's list:

David Bowie - "Rebel Rebel"

AC/DC - "Down Payment Blues"

Black Sabbath - "Spiral City Architect"

Bowie was a given, he was glam, that song is riffy and I remember it as a child growing up, I loved it then and love it now and my daughter's both love that song. And it's Bowie...

AC/DC influenced the sleazier side of rock n roll, arguably there would be no Guns 'n' Roses without them (Aerosmith deserve joint credit for them as well). They were the dirt under the fingernails, the boys that kept it real and they are solely responsible for Aussie rock, something that just keeps giving the World seriously kickass rock bands. "Down Payment Blues" is their finest moment, riffs, humour, life on the wrong side, it is raw like an open wound and whilst I would say that it is more serious than AC/DC usually are, it is a monster song off an underrated album.

Black Sabbath were a tough one to not include because they are the start of heavy metal. They were the beginnings of the music that I love and despite songs like "Paranoid" being over played, when I hear it for the first time after a few years, I get those feelings that take me back to my discovery of heavy metal, a new scene and of my first real musical love that I discovered for myself, a music that consumed me for life. I was torn as to what to pick as there are so many Sabbath songs that I love "Children of the Grave", "Into the Void", "Sabra Cadabra", "NIB", "Paranoid"... I decided to go with an unusual Sabbath song to show their diversity, that they weren't the pure doom merchants they are portrayed as, they had layers and levels that people on the outside didn't see.

My list is far from right, I am already trying to work out where to put Led Zep "Kashmir" and my daughter has suggested "Bat Out of Hell" should be in there and someone else asked where Pink Floyd is.

Despite being a huge audiophile, I can't make a list that I am happy with, even now I am taking my list apart!

Any thoughts or suggestions are welcome!