Boris by far. Other ones are Centuries and Pray For Teeth cause they shared gear and they had a wall of amps. First time I saw Thrones open for Sleep it was loud. Cloud Rat and Thou were loud. A lot of stoner/sludge bands are loud but those really stuck out.
8/29 LSD and the Search for God
9/9 Creepers/Tony Molina/Drag Majesty
10/25-26 Thou & The Body