I'm going to go with a band that should appeal to more than just the Metal-heads, whilst still being pretty heavy, and unknown. Formed originally as Hydrodjent, a solo project of Indian musician Keshav Dhar, it has evolved into a full band featuring Keshav, alongside Dan Tompkins, the vocalist of Tesseract, US based drummer and solo musician Anup Sastry and Mumbai based guitarist Devesh Dayal and bassist Krishna Jhaveri.
Skyharbor are part of the modern progressive metal/rock scene, utilizing extended range guitars for the heavily downtuned "djent" sound, but similarly to many of the bands in the "djent" movement, they are very atmospheric. Dan has a tremendous vocal range, verging on being pop-like. The below song is one of their most accessible, and one of their best.
I've pushed this band on a couple of other threads and am unashamedly gonna plug them here too.
I've loved punk since it first reared it's ugly head back in the 70's, and have followed it through to the modern day through all the various different genres and sub sections (Oi, Ska-punk etc). There have been many great and varied bands over the years, but these guys are definitely the best thing to come out of the UK punk scene in recent years.
If you like catchy, sing-along, melodic punk music then these will without doubt appeal to you. OK they look fucking weird, but punk was always about "Fuck what you think, we'll do it our way". Sums this lot up perfectly.
Steve Albini project so anyone familiar with his work in Big Black or his numerous other projects will have an idea of what to expect. Repetitive, heavy distorted minimal noise rock with the treble turned way up and prominent drums.
'Post-Hardcore' band from Michigan which incorporates spoken word poetry and short fiction in their songs as well as bringing in elements from different genres. Definitely a band that is near impossible to categorise.