I’m happy with Windows 7.
For Mac OS, 10.8.4 is highly recommended. The most recent updates that Apple has made fix some GPU issues.
From: After Effects Mail List [mailto:AE-List@media-motion.tv] On Behalf Of Patrick Siemer
Sent: Thursday, 15 August 2013 13:43
To: After Effects Mail List
Subject: Re: [AE] best flavor of windows for AE. CC.
As I piece together my first ever PC build with hackintosh dual boot drives the question of what versions of Windows and OSX are "the best" for AE CC.. I eagerly await the hive mind opinions