Free edition of Overloud's TH3 Custom Guitar Effects Suite.

I downloaded this late last week and the sounds are very nice. I didn't try all of the presets but I particularly liked the clean preset and the crunch one was also good. Of course you can dial in your own sounds as well. Here's what the promo says about it:

"Exclusively produced for Time+Space by Overloud, the TH3 Free Edition gives you the opportunity to experience this guitar amp simulator for yourself. Delivering the same features as the full version of TH3, but with fewer models and presets, this free plug-in includes:

3 guitar amplifiers.
3 guitar cabinets.
4 pedal and rack effects.
2 microphone models, with up to four mics on each cabinet.
15 presets.
4th generation analog emulation technology, with proprietary nonlinear processing algorithms.
3D, gap-less positioning of microphones and room simulation.
Advanced cabinet emulations with ReSPiRe 2 technology.
Easy to build or modify your own signal path.
Intelligent MIDI controls.
Built in Looper."

This is available not only in various VST formats but also in AAX and RTAS format.
Here's where you can download it:

Overloud Exclusive TH3 Time and Space Free Edition(Download) - Time+Space | Virtual Instruments, VST Plug-ins, Effects Plug-ins and Samples for Music Production

You do have to sign up for an account using your e-mail but they don't spam you. Please note that this software is only available until August 14th.