best distortion plug

[3nki <3nki@modaldub.net>]

sorry if this has already been discussed...

i'm looking for a good distortion plug-in, or an amp-modeler that  
essentially can function as such. something that can produce a heavy,  
fuzzy guitar-type distortion, though i'm going to use it for other  
instruments obviously.

anyone had any good experiences with such a thing? in my experience  
it's one of the harder good plug-in types to find.

thanks for any advice/comments!

-3nki