Me and upgradecap have had numerous ones
including one about me being really high and playing fable 3 at the same time running a commentary, that was great.
There was also another one I won't be sharing, unless of course certain circumstances come into play
EDIT: I've also had interesting chats with my friend Champion_Thomas, including accidentally leaking my serial for some dlc
DOUBLE EDIT: Then there was the discussion on Cleverbot's perspective on John Madden and the Antimadden
TRIPLE EDIT: There has also been an amazing discussion on ads in games courtesy of GFWL
QUAD EDIT! KO!: A final awesome discussion was the fury my friend exerted after buying a game for £30 and it went on sale later that day for like £10