It's interesting that people were saying the first one is Engl. I guess because we have this predisposed notion that Engl's are fizzy and scooped, and generally not seen as something that records well.
Well I can tell you that;
1. Marshall
2. Peavey
3. Engl
They all have their merits, and they all have qualities that would make them the best choice for certain mixes. I love the Marshall's aggression and natural scoop. The mids are around 12 o'clock on that motherfucker too and it STILL sounds really thrashy and percussive. I'd probably use it for standard tuned stuff, or anything down to about D, but anything lower it would start to become a little... I dunno actually, saying that, this clip is in C and I still really dig it.
The Peavey was obvious, I'm not surprised you nearly all got that right, you just can't dial out that 5150-ness no matter what you do. I love this amp to death, it's got such presence in a mix and the mids are in EXACTLY the right place, even if you're tuned way the fuck down.
The Engl is often my favourite really. I have an obsession with note definition and bite, and it's got that in spades. It's a little bloaty in the low mids but that disappears the moment you start adding EQ's and compression etc.