n.
1. Music A short rhythmic phrase, especially one that is repeated in improvisation.

riff [rɪf] Music
n
(Music) (Music / Pop Music) (in jazz or rock music) a short series of chords
vb
(Music) (Music / Pop Music) (intr) to play or perform riffs in jazz or rock music
[probably altered and shortened from refrain]

Ahhh... The old Riff! Be it the classic intro to 'Smoke On The Water', The Fuzz tones of 'I Can't Get No Satisfaction' or Slash's single note exercise that became 'Sweet Child 'O Mine'. Everybody loves a riff.

So... Which are yours?

Always loved the Les Paul and cocked wah sound on Money For Nothing:



Appetite For Destruction by Guns N Roses was choc full of great riffs:



Cool riff from Iron Maiden:



Here's a seriously cool riff from a very short lived UK band:



Lets see some of your favourites...