TSE808 can be used in front of an amp-sim to tighten up the low end and get some extra boost on leads.
Price: Free. It's available for Windows and Mac OS X in VST and AU plug-in formats.
06 Jan 2013 TSE Audio releases TSE B.O.D v2.0 (incl. 64-bit)
18 Jan 2010 TSE Plugins updates X30 to v1.6