I love Mammatus! Their self-titled was easily a highlight of 06. Dragon of the Deep is pretty ****ing awesome, they roll on and on like Om and Sleep's Jerusalem but the sounds a lot more spacier. Very cool indeed.
Must get the new one.
Acid King are particularly good to check out if you haven't already. I really enjoy Busse Woods.
Sons of Otis are an interesting band, SpaceJumboFudge is about as intergallactic as things get.
Warhorse are awesome too, the closest of these 3 to HoF. As Heaven Turns To Ash is a great listen.
Google Blog Search for help finding albums.