The great winner of the survey is without any doubt LePou, who has been developing guitar amp simulation plug-ins for several years. They support both Windows and OS X platforms and are available in 32 and 64-bit VST and Audio Unit versions! The catalog offers Marshall (HyBrit), Mesa Boogie (LeCto) and ENGL (Le456) simulations, as well as custom amps like the LeGion. Also note the presence of LeCab, a speaker and microphone simulation based on convolution technology (uses impulse responses). If you don't know LePou plug-ins yet, go try them out now!
The runner up in our survey is Guitar Rig's free version from German manufacturer Native Instruments. This "Player" version includes only one amp, the Jump, which is a Marshall simulation and includes a dedicated speaker cabinet. Among the effects provided, you'll find two different delays, a Tube Screamer simulation, a volume pedal, a limiter, noise gate and noise reduction systems, a compressor, two different EQs and a filter, a chorus/flanger, and a reverb. Native Instruments also included Studio Tools (LFO, step sequencer, etc.). The plug-in is available in VST, AU, AAX, or RTAS format and supports Windows and OS X.
The third place goes to the free version of the famous Amplitude 3, which is called Custom Shop because it gives you the possibility to buy any virtual gear besides the 24 already provided. Without paying a single cent, you get nine stompboxes, four amps, five speakers, three microphones, and two effect racks. It's up to you to take out the credit card and add additional amps or stompboxes! RTAS, VST and AU formats, 64-bit Windows and OS X support.
It shouldn't come as a surprise to anyone that Line 6 is among the top rated with the free version of the Pod Farm. It provides two guitar amps (JCM-800 and Fender Deluxe Reverb), two speakers (4x12 Marshall and 1x12 Fender), two bass amps (Ampeg SVT and B-15A), two bass speakers (4x10 Hartke and 1x15 Ampeg), 13 stomboxes and effects (LA2A, Cry baby, Digital Delay, Cavernous Reverb, etc.), two mic preamps (API and SSL) plus Dual Tone, and A/B/Y box features.
TSE Audio are freeware specialists and their amp simulations X30 and X50 seem to be well appreciated among our readers. The X50 aims to reproduce the tone of a "famous American amp" consecrated to metal. The X30 simulates a German hi-gain preamp. The only thing we miss, until now, is Apple support. Do note, however, that they also offer free distortion pedals that support both Windows and OS X!
SimulAnalog are the creators of a plug-in suite that simulates plenty of well-known gear among guitar players: Boss DS-1, SD-1 and Tube Screamer overdrive/distortion pedals, Oberheim PS-1 phaser, Univox Univibe and two amps (a '69 Fender Twin, and a Marshall JCM900 Dual Reverb). The only criticism we can make is that these plug-ins are only available in VST format for Windows.
True, Boogex is certainly not the best-looking plug-in in its category, but some of our readers chose it for its sound. The plug-in allows you to EQ the signal before it reaches the amp simulation, which can be useful with some instruments. It provides comprehensive features, with Tone, Drive, Dynamics and Phase controls that, according to the developer, allow you to get a wide range of overdrive effects. Even if Boogex is provided with its own impulse responses, it can load impulse files in the cabinet/microphone section.
The NRR-1 is a tube-preamp simulation equipped with three different channels. It is available in VST and AU format, both in 32 and 64-bit for Windows and OS X. The Anvil was conceived by Andy Zeugs and also offers a tube-preamp simulation.
7% of our readers use the amp simulation provided with their sequencer, 7% use another software tool that is not listed here.
The links leading to the corresponding developer websites are available in the forum.