What song/s would you recommend everyone should have in their music collection?

I'll give you a few just off the top of my head:

Led Zeppelin, Going to California

Pink Floyd, Comfortably Numb

Jimi Hendrix, The Wind Cries Mary

Creedence Clearwater Revival, Proud Mary and also Lodi

Tom Petty, Free Fallin'

The Beatles, A Day in the Life

Rolling Stones, Sympathy For the Devil

And if you like country:

Merle Haggard, The Way I Am

Marty Robbins, Singin' the Blues

Hank Williams, Long Gone Lonesome Blues

Hank Thompson, Wild Side of Life

Ray Price, Crazy Arms

Willie Nelson, Blue Eyes Crying in the Rain

I could make a huge list if I thought about it for a while! :)

Seal - Kiss from a Rose

Led Zeppelin - Immigrant Song

Smashing Pumpkins - Today

Massive Attack - Unfinished Sympathy

Frankie Goes to Hollywood - Relax

Carl Orff - Carmina Burana

Mr Scruff - Get a Move On

Blink 182 - What's my Age Again?

Air - Ce Matin La

Joe Satriani - Surfing With the Alien

Santana feat Rob Thomas - Smooth

Jane's Addiction - Been Caught Stealing

The Prodigy - Poison

Dr Dre - Aint Nuthin but a G Thang

Tenacious D - Wonder Boy

Charles Mingus - Goodbye Pork Pie Hat

Jimi Hendrix - Crosstown Traffic

Primus - Jerry was a Racecar Driver

Frank Zappa - Keep it Greasey

Dream Theater - The Glass Prison

Oasis - Wonderwall

Steppenwolf - Born to be Wild

Gary Moore - Parisienne Walkways

Van Halen - Hot for Teacher

Michael Jackson - Beat it

Toto - Africa

Focus - Hocus Pocus

Jaco Pastorius - Continuum

Metallica - Enter Sandman

Roni Size - Brown Paper Bag

London Elektricity - Power Ballads

Cypress Hill - Rock Superstar

William Orbit - Water from a Vine Leaf

Racer X Time Before the Sun

I could be here all day

All Time Low- Six feet under the stars

3oh!3- Dont Trust Me

Boys Like Girls- Learning To Fall

Carolina Liar- Show Me What I'm Looking For

Hawthorne Heights- Desperation

Kings of Leon- Use Somebody

Mat Kearney- Closer To Love

Matt Nathanson- Come on get Higher

Paramore-Adore

The Academy is..-About A girl

The White Tie affair- Candle "Sick and Tired"

Theory of A deadman- Not meant to be

Thriving Ivory- Angels on the moon

Hotel California, The Eagles

Comfortably Numb. Pink Floyd

Parallel Lines, Blondie.

All to Jesus I surrender

Amazing Grace

And it holds, my anchor holds

It's still the blood

At The Cross

Because He Lives

Blessed Assurance

Born Again

Calvary Covers It All

Christ For Me

Christ Is All I Need

Dare To Be A Daniel

Face To Face

Fairest Lord Jesus

Faith Of Our Fathers

Follow, I will Follow Thee

Marvin Gaye

The Temptations

The Four Tops

The Supremes

Stevie Wonder

Martha Reeves and the Vandellas

Mary Wells

Smokey Robinson and the Miracles

Junior Walker and the All Stars

I love Motown.....would never be without it.

The Breakup Song- Greg Kihn

Frank Sinatra's Songs

Is This Love? - Whitesnake

Nothing Else Matters - Metallica

Sweet Child of Mine- Guns n Roses

Cherry Pie - Warrant

Ernie, The Fastest Milkman in the West.