This lick is one that I made up recently, when practicing, and I think it sounds pretty cool. It's the sort of riff you can play in most genres and it still sounds great, so if you're into shred, metal, even blues, check this out. You could even use it as a warm up exercise.
I use dropped C tuning, but the lick doesn't use the 6th string, so it will work fine in standard tuning, or dropped D, or even dropped B, or D standard, or whatever...
Remember, the first two notes are still the same length as all the others (minus the last note which is held), but they come in right at the end of the previous bar, so they kind of lead in to the lick. You don't even have to play those notes, but i think it sounds better with them.
I play it at about 120-140 bpm, but make sure you start playing it slowly, otherwise you'll mess it up and I don't want my lick getting messed up. More importantly, if you start playing it slowly, then you'll play it cleaner when you do get it up to speed.
You will notice it lick uses a bluesy version of the standard C minor (D minor if you're in standard or dropped D tuning) pentatonic scale. This is commonly used by shredders like Yngwie Malmsteen, and, more noticeably, Alexi Laiho (From Children Of Bodom and Sinergy).
If you move this lick up 4 frets to the E minor pentatonic position (F# if you're in standard or dropped D tuning) then there is an awesome pinch harmonic on the last note. It's easy to find, and you'll know when you've got it, because it sounds insane.
Obviously, you can use the lick in whatever positions, keys, etc. you like, and I encourage you to change it, and make it your own. It would be a shame if everyone played stuff they learned off of the internet all the time withought changing it at all.
I hope you liked this lick, and if you need any help or want any more licks or whatever, then comment me or email me at email@example.com.