Remember that first time you squashed into an audience of a few thousand after months of preparatory song-learning, not knowing what you were about to hear but praying it would be the one you essentially bought the ticket for? Of course that could be one song or an entire album, but back when you start going to gigs or getting into a certain band you've usually no idea what the 'must play' songs from their given catalogue are, and so instead we stand waiting - already psyched by the spectacle of such an event - for any number of crowd-pumping tracks to drop; the resultant pop being enough to tear the roof off. It's long remained a pastime for rock fans and metalheads of any persuasion to argue until the crack of dawn which of their most beloved (and probably seared into their flesh) bands are the best; and yet amongst larger debates surrounding the likes of Metallica vs. Iron Maiden or The Beatles vs. The Rolling Stones sits the building blocks of such a thing - which bands possess the biggest riffs? Of course 'biggest' is a potentially strange term when you start applying it to any sort of ranking system - because are we talking about technical ability, dynamic-contrast and volume, catchiness or just high production value? It's all of the above, and then some. The riffs contained herein are the embodiment of the opening statement - the parts of a song you'll seek to learn as soon as you get your hands on any instrument, and the ones that make us do that nose-crunching half sex-face purely out of something just depressing your inner "Oh hell yes" button, all the while cementing themselves in time as the best the genre can offer for veterans and newcomers alike. A tall order? Most likely, but if the only bad to come out of such an expedition into the annals of metal's archives is a few more debates into the wee hours, then it's about time we got started.