I really like the Compact Distortion VST:
VST plugins [slim slow slider presents]
and have even employed it as a 'bass-inator,' setting the two 'filters' to something like 200hz high and 20hz low. It sounds better to me than any of the 'octaver' VSTs (at least for creating a 'bass guitar' sound).
For 'lead guitar,' it's got a unique voice.