Greatest riffs

Hi
What is everyones favourite song riffs? Whether it be opening or whatever.

I'd say my favourites but I can't think of any

My favorite riff of all time has to be the one from ''Be Quiet And Drive'' by Deftones. Very uplifting, and kind of mesmerizing too.

Currently, one of the riffs in the middle of Advent by Opeth.

favourite: Neil Perry - Nine minutes of non-fiction