With finals in full swing I don't have much time to write, so I'll just point you in the direction of a couple of excellent videos. The first is just a hodgepodge of the best tirades of NFL coaches, including Dennis Green, Jim Mora, and Mike Ditka.
The second one is just the best of Jim Mora. I once linked to the Jim Mora Playoffs Clip, but this one is longer and has a greater variety. Though for my money you can't beat: "Playoffs? Don't talk about playoffs. Are you kidding me? Playoffs? I'm just hoping we can win a game."