Source is at 49 seconds:

highqualitygifs Dave Chappelle Samuel Jackson beer gif: http://i.imgur.com/cBhtlLQ.gifv

Thank you preggit for making this gif:

http://reddit.com/r/HighQualityGifs/comments/2wzvle/when_i_see_a_new_user_start_to_post_here/

Thank you preggit for making this gif:

http://reddit.com/r/HQGClassic/comments/30hj1m/when_i_see_a_new_sub_devoted_to_high_quality_gifs/

Thank you preggit for making this gif.

Dave Chappelle is parodying this:

Thank you Butcher_Of_Hope for making this gif.

Here's the scene. Note McConaughy and Kevin Spacey:

You can't handle the truth:

http://pandawhale.com/post/44474/jack-nicholson-you-cant-handle-the-truth-gif

Samuel L Jackson brought that intensity to Snakes on a Plane too:

http://pandawhale.com/post/59026/samuel-l-jackson-snakes-on-a-plane-gif