Here is a list I was afraid to make, is way too long

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Acmebargig.com has one of the largest choice of virtual amps, each one with it's own character, and you know what ? ALL SOUNDS GREAT !(easy on CPU also)
Classic Hybrid Line:
Dick Head - is the first release in AcmeBarGig's Classic Hybrid series. Dick Head is a Head ONLY so you will need to use some external cabinet modeling.
Even when it’s cranked to insane levels it still retains its clarity and responds exceptionally well to the nuances and subtleties in your playing.
Meat Head - inspired by the amplifier power-houses that defined the tones of Classic Rock and Heavy Metal from the '60s to now. Meat Head is a Head ONLY so you will need to use some external cabinet modeling.
Knuckle Head - capable of kicking out tones that range from glistening cleans, to SRV and Yardbirds style smokin’ hot crunch, right through to punishing high gain destruction.
Knuckle Head is a Head ONLY so you will need to use some external cabinet modeling.
Brain 2 - if you're in the mood for some Classic Rock tone, or want that vintage crunch, then Brain 2 is your way to go.
Brain 2 is a Head ONLY so you will need to use some external cabinet modeling.
Gimme Head - inspired by the classic tones of the 1970's Punk movement, even dressed in a Leopard Skin Thong and Fishnets

Gimme Head is a Head ONLY so you will need to use some external cabinet modeling.
Tamla Head - inspired by Motown Records' The Funk Brothers one of the most important bands, session or otherwise, in music history.
Tamla is clean and reserved, full of character and shrouded in musical history but AcmeBarGig added an extra gain section just to make sure that Tamla was good for other uses as well.
Tamla Head is a Head ONLY so you will need to use some external cabinet modeling.
Pecker Head - perfect for thick, saturated riffs and crunching power chords. AcmeBarGig says that Pecker Head might just be the truest to this Classic Rock sound.
Pecker Head is a Head ONLY so you will need to use some external cabinet modeling.
Mr. Tater Head is a Classic Rock-inspired amp with some impressive extra tweakability.
Mr. Tater Head has three different gain controls - Bass Gain, Mid Gain and Treble Gain - as well as the standard Bass, Mid and Treble controls on its tone stack. These extra gain controls mean you can really get in to shaping the sound of the saturation.
Mr. Tater Head is a Head ONLY so you will need to use some external cabinet modeling.
Preampus Metal Line:
Razor Head is the first amp from AcmeBarGig's "Preampus Metal Line" of heads.
Razor is completely unpredictable in the sense that one turn of a knob could lead you to a whole new world of tones.
Series 60 is the second amp from AcmeBarGig's "Preampus Metal Line" of heads. Series 60 comes with a built-in Drive Amp and you have some scary potential for gain, the Death Metallers out there should LOVE the Series 60!
C-15 is a METAL Head, nothing else. If you wanna play Jazz, go elsewhere, cause C-15 don’t play Jazz, or even classic rock, It wants METAL and nothing else.
Clean Amp:
Tribe - designed to give you pure, crystal clear clean tones with the ability to load external pickup/acoustic guitar impulses.
Shred SuiteProbably the most impressive of their free products.The
Shred Suite features six versatile amp heads ranging from warm, sweet, clean tones to hair-raising metal thunder:
Shred:

A metal and hard rock powerhouse, the SHRED head is all about rocking out.
Enthalpos Median:

Enthalpos is all poweramp, the wildcard of the bunch.
Supersound 1972:

Dark and doomy, the Supersound is right at home churning out early Sabbath-style ethereal drones.
Marvel:

The Marvel is an all-rounder, capable of crystalline cleans and thunderous British crunch.
Quarter:

Pure, classic clean tones and fantastic mild break-up, the Quarter is a bluesman's dream.
Honken:

The Honken kicks out Classic British tone, fantastic for sweet, glassy cleans and great crunch.
Interchange Nearly Every Aspect Of Every Head
Perhaps the most interesting feature of Shred is the feature that allows you to create a head that suits you: AcmeBarGig's 'Frankenamp' technology allows you to select the parts from any of the other heads and mix and match them for a sound all your own.