Deerhoof
I saw this band last night. I had heard the name but had never heard the music. I was enthralled. This is not easy listening. I guess you could call Deerhoof post punk, noise, experimental, electronic, etc... but there is a subtle aspect of pop in the way they (sometimes) use melody. This is not at all dark though. It is very playful and sometimes silly. It is very unconventional in any case.
They are amazing musicians, especially the drummer and they are incredibly tight as a band. They play in many different time signatures and bend the tempo constantly. I guess what really appealed to me was the complete freedom of their music and their live performance. They have been around since 1994 and they have recorded around twenty albums so I have a lot of listening to do! Here is an example of the joyful insanity of their music. This is a song that they played last night called Basket Ball Get Your Groove Back from their 2008 release Offend Maggie.