I suppose any list like this is subjective, depending on the genre of music you like, your age & what musical influences you had as a young 'un. As someone who was born in the 50's, grew up in the 60's & early 70's, I tend to lean heavily towards anything by guitarists from that era. George Harrison, Eric Clapton, Keith Richards & the very under rated (to most people) Richard Thompson & I think Mark Knopfler deserves a mention as well.
Richard's riff at the beginning of this still sends chills down my spine & has done since I first heard it back in 1969
There are TOO many. Not sure the list is correct or exhaustive. It could be 200 riffs long and not please everyone. A good start though!