This is a pretty local festival for me, haven't gone yet, but have heard good things over the past 3 years.
Disclosure - October 12 - Reno, NV. Treasure Island Music Festival - October 19 - San Francisco, CA. Portugal, The Man - October 22 - Reno, NV. Cut Copy - October 31 - Reno, NV. Phoenix w/ Alt-J - December 5 - Reno, NV.