Woah - how did I not know about those guys? Instant cd purchase...
I second most of your other suggestions - there really is a lot of quality out there. Meshuggah is a bit of an acquired taste, but they have recorded possibly the greatest metal video of all time:
I'll give Meshuggah another try..
I must admit I can't remember how I found 'em - either a record company mailing or an event mailing I guess - they've got members of a few other bands in their lineup and haven't been going that long. I've seen 'em a few times recently as the headline act- last december at the Borderline (a really small venue a stones throw from the building site that was the Astoria), and back in April at the Garage (kinda size venue Lacuna Coil and Accept have done in the last few years) - not full by any means but a decent turnout. I guy I often see was chatting to 'em at a meet n greet, sounds like they've a new album coming out later this year, so I expect there'll be a tour after that. Tho' other than a support slot with Kamelot and Evergrey last year (which I've not heard much of either, so another reason I'd not heard of 'em before) - and that was just London and Nottingham- they've only done those few London gigs. Unsurprisingly they seem to do a lot of gigs in Scandanavia, including some larger headline slots:
http://www.amaranthe.se/?go=tourdates#Main
- looks like they were on at last years Female Metal Voices fest too.