Best amp for heavy distortion

[DropD]

I'm in the market for a combo amp that would give a really good distortion sound. It seems every metal band that have a great distortion sound (mainly Metallica) are using Mesa Boogie amps. So I tried a Nomad 55 and it was quite a good amp, sounded terrific for soloing, but was very muddy in the when mute-picking on the big E string. I tried toying a bit with the tone controls and couldn't make it work. It's too bad cause it was really a cool amplifier, with 3 channel, recording out, separate level control for solo mode, everything I'd need. But just too muddy on the low-end. I suspect a Dual Rectifier model would be better on that aspect, but I couldn't try one (or is it that I didn't ask for it since the price was 3 times what I wanted to pay). Is this right? Would a Dual Rectifier do everything I want?

The next amp I tried was a Line6 Flextone XL, the one with 2 12" drivers. It sounded quite good, specially the dual rectifier mode, but I don't know, there's something about this amp that make it sounds artificial (well actually it is artificial, it's digital modeling). But for the price (999$), it was the only good sound amp I could find.

Do you guys have a suggestion for an amp that would give a killer heavy metal sound, in the 800-1300$ range, a combo with 1 or 2 12" drivers. I'm thinking about trying a JCM2000 TSL (I really need 3 channels), but all the Marshall I tried had this overly bright tone which I don't like. Anyway... suggestions welcome.