Amp manufacturer Ignite Amps are a pretty forward-looking company, creating highly-detailed VST versions of their products and giving them away from free on the internet (on ya, Ignite!).
There latest offering, the NRR-1 guitar amp VST kicks all sorts of ass. Whereas amp simulations often have a tell-tale fizzy quality that separates them from their hardware-based brethren, the NRR-1 sounds like a big, fat, awesome tube amp. (The NRR-1 is an emulation of a real amp built for Fleshgod Apocalypse guitarist Cristiano Trionfera). Three channels, clean, rhythm and lead, each with fully separated controls, mono/stereo processing support and fully automatable controls, make this probably the most killer amp VST out there.
PROS: Sounds friggin’ brilliant
CONS: Absolutely none; this thing rocks.