Very unique one is Detektivbyrån, they are split up, but one, maybe more, of their members are now Wintergatan. They use atypical objects and machines to create musical sounds.

Whatever drug abusers do the Splatoon OST. Especially in Splatoon 1, they have a very unique and special kind of music and I am here for it, I love Anarchy Rainbow, Tide Goes Out, Calamari Inkantation, it's weird and unique but it works. Other than that, since I'm not too into music, I hardly even notice any artists unfortunately.
Hopefully I can change that.

Al Yankovic. He's weird in a cool way.

well uh, weird al duh.
Seriously though a niche one i like is soshi soucy