Links to watch, listen, or get the PowerPoint slides. These links will take you to the official Splunk .conf section for that year.
2017 – http://conf.splunk.com/sessions/2017-sessions.html
2016 – http://conf.splunk.com/sessions/2016-sessions.html
2015 – http://conf.splunk.com/speakers/2015.html
2014 – http://conf.splunk.com/speakers/2014.html