Rainbow's Spotlight Kid from The Final Vinyl LP, sperb

Evidently Chicken Town - John Cooper Clarke
t.h.i.s.i.s.h.a.r.d.c.o.r.e - pulp
Gimme shelter - Stones (mentioned by Yed already, but warrants another shout)
Kick out the Jams - MC5 (live version with the rude words )
Ceremony - New Order
Ch Ch Check it out - Beastie boys
Nebraska - Brucey
The Stranger - Lord Huron
Skinny Love - Bon Iver

Rage Against The Machine - Bombtrack
Jay Z/Kanye/Frank Ocean - No Church In The Wild
Refused - New Noise
Kanye West - Black Skinhead

Natural one - Folk implosion
White winter Hymnal - Fleet foxes

Underworld - Born Slippy

Motorhead - Killers

My twopenn'oth

'This Charming Man' - The Smiths
'Bigmouth Strikes Again' - The Smiths
Town Called Malice' - The Jam
'The Riverboat Song' - Ocean Colour Scene
'You Really Got Me' -The Kinks
'Be Gone'- British Sea Power

For me it's Gimme Shelter by the Rolling Stones

I also like She sells Sanctuary by the Cult (long version) and Do anything you wanna do by Ediie and the hot rods.

As for riffs, to many to choose from.

90% of Northern Soul tracks including:
Bari Track - Doni Burdick

Can you hear me knocking by the Rolling Stones
Stay With Me by the Faces
5:15 by the Who
Carry On by Crosby Stills and Nash
Fresh Garbage by the Spirit
Roadhouse BLues by the Doors
For those about to Rock ACDC
Reelin in the Years by Steely Dan
Pump it Up Elvis Costello
there are way too many to mention

Back in black AC/DC
its a long way to the top if you wanna rock'n'roll AC/DC
Iron man Black Sabbath
smoke on the water Deep Purple

Forgot
The Trooper Iron Maiden

good choice, i will add to that Powerslave, Women in uniform & Moonchild

Radiohead - Just (Also has a very impressive outro too!).

And despite some of you mentioning The Who, nobody mentions:

Baba O'Riley

Best intro of all time