First, i think that you need a 'larger vocabulary'. Second, do you have something to say? So few guitar players have anything to say, even those with huge vocabularies, that they just re-hash licks that they've learned from records. So learn more licks, adapt them, and when you solo in a song, try to think of something appropriate to the song.... as a lead guitar player your opportunity to solo is your chance to make the song 'better' and to add your voice and perspective to the song... though so many think it is just a chance to wave their big d@&ks around at try to show off for the chicks.
As a songwriter I find recycled riffs to diminish the song, not to help make it better or more memorable. As a producer I won't allow them on my records, which is why I say you need a bigger vocabulary from which to be able express yourself. It is valuable to learn the classic riffs, but more as a tool to learn how to create riffs of your own.
"I believe that entertainment can aspire to be art, and can become art, but if you set out to make art you're an idiot."
Show business: we're all here because we're not all there.