LePou’s series of amp sims are ranked very, very high on my favorite VST plugins list.
I use them on my guitars, I use them on my synths, samples, anything that needs some sort of dirtyfication. Now LePou has released another sim called LeCto.
LeCto is a freeware Mesa Boogie Rectifier sim in VST format, available for Windows. It seems to work well in most hosts, except for Sonar in which some users may experience issues. Also, note that this is just an amp sim (no cabinet), so if you’re going to use it with your guitar, make sure you use a proper cabinet IR in your effects chain.
Here are a few additional tips by LePou:
You’ll notice that the modern mode has a “Resonance” control. This will help you control the low end depending on the IR you’ll be using. You’ll most likely set it to 0 with Catharsis IRs for instance but you’ll probably need to crank it a little bit with Redwire IR. I don’t wanna get technical here but it is related the way the IRs have been captured (with or without power tube/speaker/cabinet interaction).
The plugin is available for download on LePou’s blog.