top 5 most recognizible guitar riffs

[Wolf]

Dirty Water - Standells
You Really Got Me - Kinks
Psychotic Reaction - Count Five
The Pusher - Steppenwolf
Don't Call Us, We'll Call You - Sugarloaf

 

[Death on Credit]

I don't know about Psychotic Reaction or Dirty Water being all that recognizable on a mass level, but I love you for including them.

I'd go with:
1) Satisfaction by the Rolling Stones
2) Day Tripper by the Beatles
3) Johnny B. Goode by Chuck Berry
4) Purple Haze by the Jimi Hendrix Experience
5) Sunshine of Your Love by Cream

Special mention to Louie Louie, You Really Got Me, Smoke on the Water, Iron Man, and Whole Lotta Love.